Black Box Cable Box PCW22A R3 User Manual

AUGUST 1998  
PCW22A-R3  
PCW22C-R4  
Protocol Converter  
A/S-2G  
A/S-2G  
B
PORT  
CDB  
TXD RXD RTS CTS DTR DSR TXC RXC PWR  
PORT A  
TXD RXD RTS CTS DTR DSR CDA  
Order toll-free in the U.S.: Call 877-877-BBOX (outside U.S. call 724-746-5500)  
FREE technical support 24 hours a day, 7 days a week: Call 724-746-5500 or fax 724-746-0746  
Mailing address: Black Box Corporation, 1000 Park Drive, Lawrence, PA 15055-1018  
CUSTOMER  
SUPPORT  
INFORMATION  
 
PROTOCOL CONVERTER A/S-2G  
INSTRUCCIONES DE SEGURIDAD (Normas Oficiales Mexicanas Electrical Safety Statement)  
1. Todas las instrucciones de seguridad y operación deberán ser leídas antes de que el aparato eléctrico sea operado.  
2. Las instrucciones de seguridad y operación deberán ser guardadas para referencia futura.  
3. Todas las advertencias en el aparato eléctrico y en sus instrucciones de operación deben ser respetadas.  
4. Todas las instrucciones de operación y uso deben ser seguidas.  
5. El aparato eléctrico no deberá ser usado cerca del agua—por ejemplo, cerca de la tina de baño, lavabo, sótano  
mojado o cerca de una alberca, etc..  
6. El aparato eléctrico debe ser usado únicamente con carritos o pedestales que sean recomendados por el fabricante.  
7. El aparato eléctrico debe ser montado a la pared o al techo sólo como sea recomendado por el fabricante.  
8. Servicio—El usuario no debe intentar dar servicio al equipo eléctrico más allá a lo descrito en las instrucciones de  
operación. Todo otro servicio deberá ser referido a personal de servicio calificado.  
9. El aparato eléctrico debe ser situado de tal manera que su posición no interfiera su uso. La colocación del aparato  
eléctrico sobre una cama, sofá, alfombra o superficie similar puede bloquea la ventilación, no se debe colocar en  
libreros o gabinetes que impidan el flujo de aire por los orificios de ventilación.  
10. El equipo eléctrico deber ser situado fuera del alcance de fuentes de calor como radiadores, registros de calor, estufas  
u otros aparatos (incluyendo amplificadores) que producen calor.  
11. El aparato eléctrico deberá ser connectado a una fuente de poder sólo del tipo descrito en el instructivo de  
operación, o como se indique en el aparato.  
12. Precaución debe ser tomada de tal manera que la tierra fisica y la polarización del equipo no sea eliminada.  
13. Los cables de la fuente de poder deben ser guiados de tal manera que no sean pisados ni pellizcados por objetos  
colocados sobre o contra ellos, poniendo particular atención a los contactos y receptáculos donde salen del aparato.  
14. El equipo eléctrico debe ser limpiado únicamente de acuerdo a las recomendaciones del fabricante.  
15. En caso de existir, una antena externa deberá ser localizada lejos de las lineas de energia.  
16. El cable de corriente deberá ser desconectado del cuando el equipo no sea usado por un largo periodo de tiempo.  
17. Cuidado debe ser tomado de tal manera que objectos liquidos no sean derramados sobre la cubierta u orificios de  
ventilación.  
18. Servicio por personal calificado deberá ser provisto cuando:  
A: El cable de poder o el contacto ha sido dañado; u  
B: Objectos han caído o líquido ha sido derramado dentro del aparato; o  
C: El aparato ha sido expuesto a la lluvia; o  
D: El aparato parece no operar normalmente o muestra un cambio en su desempeño; o  
E: El aparato ha sido tirado o su cubierta ha sido dañada.  
2
 
TABLE OF CONTENTS  
Table of Contents  
1.0 Specifications .......................................................................................................................................5  
2.0 Introduction.........................................................................................................................................6  
3.0 Installation ...........................................................................................................................................7  
3.1 Unpacking and Inspection ........................................................................................................7  
3.2 Data Flow Control ......................................................................................................................7  
3.2.1  
3.2.2  
3.2.3  
3.2.4  
3.2.5  
3.2.6  
SW3 ...............................................................................................................................7  
SW2 ...............................................................................................................................8  
Self-Diagnostics.............................................................................................................9  
Reconfigure Switch Mode............................................................................................9  
RS-232 Pass-through Options ....................................................................................10  
Reset Options .............................................................................................................10  
3.3 Preparing A/S-2G for Connection to an Asynchronous Device............................................10  
3.3.1  
3.3.2  
3.3.3  
3.3.4  
3.3.5  
3.3.6  
Data Terminal Ready (DTR) Signal Options ...........................................................10  
Clear to Send (CTS) Signal Options.........................................................................11  
Baud Rate Options.....................................................................................................11  
Modem or Direct-to-Terminal Connection ..............................................................11  
Carrier Options ..........................................................................................................12  
Cable Requirement....................................................................................................12  
3.4 Preparing the A/S-2G for Connection to a Synchronous Device .........................................12  
3.4.1  
3.4.2  
3.4.3  
3.4.4  
3.4.5  
3.4.6  
3.4.7  
3.4.8  
Data Terminal Ready (DTR) Signal Options ...........................................................12  
Clear to Send (CTS) Signal Options.........................................................................12  
Baud Rate Options.....................................................................................................13  
Modem or Direct-to-Terminal Connection ..............................................................13  
External or Internal Clocking Option......................................................................13  
Carrier Options ..........................................................................................................13  
Cable Requirement....................................................................................................13  
Command Pass-Thru..................................................................................................14  
4.0 Operation...........................................................................................................................................15  
4.1 Asynchronous Device to Synchronous Device........................................................................15  
4.1.1  
4.1.2  
4.1.3  
4.1.4  
4.1.5  
4.1.6  
4.1.7  
4.1.8  
4.1.9  
Line Control...............................................................................................................15  
Asynchronous Input Data Format.............................................................................15  
Data Conversion.........................................................................................................15  
Record and Block Size ...............................................................................................15  
Use of Carriage Return..............................................................................................16  
Flow Control...............................................................................................................16  
Presentation of Data from A/S-2G to Synchronous Device ....................................17  
Verification of Data Reception..................................................................................17  
Line Turnaround .......................................................................................................17  
3
 
PROTOCOL CONVERTER A/S-2G  
4.2 Synchronous Device to Asynchronous Device........................................................................22  
4.2.1  
4.2.2  
4.2.3  
4.2.4  
4.2.5  
4.2.6  
Line Control...............................................................................................................22  
Synchronous Input Data Format...............................................................................22  
Data Conversion.........................................................................................................22  
Flow Control...............................................................................................................22  
Verification of Data Reception..................................................................................22  
Line Turnaround .......................................................................................................22  
5.0 Conversions and Connections ..........................................................................................................27  
5.1 Transparency Mode of Operation...........................................................................................27  
5.2 Installing or Replacing PROMs...............................................................................................27  
5.3 RS-232 Cable Chart ..................................................................................................................27  
5.4 Code Conversions.....................................................................................................................29  
5.5 Printed Circuit Board Layout ..................................................................................................31  
4
 
CHAPTER 1: Specifications  
1.0 Specifications  
Protocol — Asynchronous: TTY (ASCII)  
Bisynchronous: 2770, 2780, 3741, and 3780 (EBCDIC)  
Ports — A: Asynchronous  
B: Synchronous/bisynchronous  
Speed — Up to 19.2 Kbps (each port independent)  
Interface — RS-232 (both ports)  
Connectors — (2) DB25 (female)  
Flow Control — Asynchronous: X-ON/X-OFF or DTR/CTS interface lead (in DTE only)  
Synchronous/bisynchronous: standard BSC handshaking  
Indicators — Unit Power:  
PWR Power (LED mounted on Port B side)  
TXD Transmit Data  
Each Port:  
RXD Receive Data  
RTS  
CTS  
Ready to Send  
Clear to Send  
DTR Data Terminal Ready  
DSR Data Send Ready  
CDA Carrier Detect  
CDB Carrier Detect (LED mounted on Port A side)  
TXC Transmit Clock  
Port A only:  
Port B only:  
RXC Receive Clock  
Approvals — CE  
Power — 115 VAC, 50/60 Hz, 63 watts  
(230 VAC model available upon request)  
Size — 2.1"H x 11.5"W x 8.8"D (5.3 x 29.2 x 22.4 cm)  
Weight — 3.5 lb. (1.6 kg)  
5
 
PROTOCOL CONVERTER A/S-2G  
2.0 Introduction  
The Model A/S-2G provides compatibility between an asynchronous, ASCII coded device and a  
synchronous, EBCDIC coded device. It is desirable, prior to installation, to review the following  
checklist to ensure the appropriateness of all the devices in the system for the planned application.  
Synchronous (Bisynchronous) Side -  
Which Protocol is being used? (2770, 2780, 3741, or 3780)  
®
If IBM -- is the line to be used a Bisynchronous line? Do you have the BSC Communications package?  
Is machine code EBCDIC?  
Asynchronous Side -  
Is transmission code ASCII?  
Will it operate in TTY format (start/stop, RS-232, 7 bit, and even-odd mark or space parity)?  
The A/S-2G is equipped with two bidirectional RS-232C ports. These ports, labeled Port A and Port B,  
transfer data at up to 19.2 Kbps. Either or both ports may be connected directly to a terminal, CPU,  
or an appropriate modem. You configure each port’s operational parameters independently by setting  
DIP shunts, DIP switches, and jumpers (explained in Chapter 3.0).  
Diagnostic LEDs are mounted on the front of the unit. These LEDs are labeled Port A and Port B.  
They are directly associated with the two ports and indicate the status of the A/S-2G at the port  
indicated.  
The reset button on the back panel will cause the A/S-2G’s Z80A microprocessor to reinitialize (reset).  
6
 
CHAPTER 3: Installation  
3.0 Installation  
3.1 UNPACKING AND INSPECTION  
After unpacking the A/S-2G, inspect it for shipping damage. Should there be any noticeable damage,  
save the cartons and contact the carrier who delivered the box to place a freight damage claim.  
To open the A/S-2G, take out the four screws from the bottom. Lift off the cover. With the cover  
removed, visually inspect for components that may have been loosened in shipment. Shipping  
damage is rare, but a quick inspection is always good practice.  
Leave the cover off for installation.  
3.2 DATA FLOW CONTROL  
For the locations of the switches and jumpers, see Figure 5-2 on page 28.  
3.2.1 SW3  
Locate the set of 8 asynchronous switches labeled SW3 on the printed circuit board.  
(See Figure 5-2 on page 28.) These should be set as follows:  
Switch #l ON = echo asynchronous characters — echoplex mode.  
OFF = don’t echo asynchronous characters — normal mode.  
Set this switch ON when the asynchronous device expects to receive an echo of its transmitted data.  
NOTE  
The A/S-2G always operates in half-duplex mode on the synchronous side, so this option applies only to the  
asynchronous device.  
Switch #2 ON = echo “EOT” character.  
OFF = don’t echo “EOT” character.  
The last record received from the asynchronous device must be terminated with a “Control D” character. For this  
character to echo to the asynchronous device, switch #2 must be ON. This character is echoed only  
after the EOT sequence is sent to the synchronous device. Its echo appears as a CR LF, EOT.  
NOTE  
An EOT from the bisynchronous device will be displayed in the same way to the asynchronous device with this  
switch ON.  
Switch #3 ON = do not include CR (carriage return) character in EBCDIC data.  
OFF = include CR character in EBCDIC data  
Each block sent by the asynchronous device (except the last one) must be terminated with a CR (carriage return)  
code. If this CR code will be included in the synchronous EBCDIC data as a new line, this switch must  
be OFF.  
NOTE  
The 3741 protocol is limited to a block size of 128 characters (the block size is also the record size), thus a CR  
must be entered not later than each 128 characters.  
7
 
PROTOCOL CONVERTER A/S-2G  
Block size for the 2770/2780 is normally limited to 160, but block size is 400 if the 2770/2780 has the  
Multiple Record Transmission. Block size for the 3780 is 512.  
Switch #4 ON = sends CR LF (Carriage Return, Line Feed) to asynchronous device immediately after  
each logical end of block character (ETB, or ETX) is received from the synchronous  
side.  
OFF = Normal operation  
Switch #5 ON = Variable-length blocks. This switch causes the records sent by the asynchronous  
device to be blocked and treated as variable length, i.e. no spaces are used to pad  
out the block.  
OFF = All blocks are treated as fixed length, which would require blank spaces, if necessary,  
to complete the block size. (In 2780 multi-record blocks, an IUS character is  
inserted after each 80 characters counted. The final record is the only one that may  
be less than the block size specified).  
NOTE  
It is possible that a block will have only one record if you enter a CR after each record (2780 mode).  
Switch #6 ON = 3780 MODE  
OFF = 2770/2780/3741 MODE  
Switch #7 ON = When RAM reaches a nearly-full state, DTR (Pin 20) will be lowered. When RAM  
space is available, DTR will be raised to permit transmission to resume. Port A must  
be configured as DTE (see Section 3.2.5). When CTS from the external  
asynchronous device is ON, the A/S-2G can send data. When the external device  
lowers CTS, the A/S-2G will not send data.  
OFF = When RAM reaches a nearly-full state, an X-OFF (ASCII DC3, 13 Hex) will be issued  
to the asynchronous device to prevent buffer overrun. When RAM space is available,  
X-ON (ASCII DCl, 11 Hex) will be sent to resume transmission. Put the CTS A  
jumper to the on position (see Section 3.2.3).  
Switch #8 ON = 2 Stop Bits (asynchronous side only).  
OFF = 1 Stop Bit (asynchronous side only).  
3.2.2 SW2  
Locate the switch labeled SW2 on the printed circuit board. (See Figure 5-2 on page 28.)  
Switch #1 ON = Space compression on transmit (3780 Mode only).  
OFF = Normal operation.  
Switch #2 ON = Pass escape sequences through.  
OFF = Convert escape sequences to CR LF or FF per Section 4.2.3 on page 20.  
Switch #3 ON = No Asynchronous RTS except during bisynchronous receive (half-duplex on  
asynchronous side).  
OFF = Normal Operation (full-duplex).  
8
 
CHAPTER 3: Installation  
Switch #4 ON = Self-Diagnostics Mode.  
OFF = Normal Operation.  
Switch #5, #6—Block Size Specification.  
5
6
OFF OFF  
OFF ON  
80 Characters  
128 Characters  
256 Characters  
512 Characters  
ON  
ON  
OFF  
ON  
NOTE  
For 3741, set SW3, Switch #5: OFF (Fixed length)SW2, Switch #5: OFF, and Switch #6: OFF (128 character block)  
Switch #7, #8—Asynchronous Parity Specification.  
7
8
OFF OFF  
OFF ON  
Space Parity (always 0)  
Mark Parity (always l)  
Odd Parity  
ON  
ON  
OFF  
ON  
Even Parity  
NOTE  
The A/S-2G only recognizes a 7-bit, 1 bit parity sequence. 8-bit data, no parity is the same as  
7-bit, space parity. If you have 8-bit data, no parity, set SW2, Switches #7 and #8 to the OFF position.  
3.2.3 SELF-DIAGNOSTICS  
There are two ways to enter the self-diagnostic mode. The first method requires that you locate SW2,  
switch #4 and set it to the ON position. When you press the reset switch, the A/S-2G will display  
diagnostic information (see below) on a terminal or printer connected to Port A.  
The second method requires a terminal connected to Port A. When you type an ampersand (“&”)  
and then a pound sign (“#”), the A/S-2G will enter the Self-Diagnostics/Reconfigure Switch Menu.  
Press the “l” key to enter the self-diagnostics mode and the A/S-2G will display diagnostic information  
on your terminal.  
This is what the A/S-2G does in self-diagnostic mode:  
Displays its software version  
Checks the ROM  
Checks the RAM  
Displays the state of SW3  
Displays the state of SW2  
Displays the state of SW1 Port A  
Displays the state of SW1 Port B  
The information for SW3, SW2, and SW1 is listed in binary: 1=ON and 0=OFF.  
9
 
PROTOCOL CONVERTER A/S-2G  
NOTE  
Self-diagnostics will normally display the switches as they are set on the printed circuit board. If the switches  
were reconfigured (see Section 3.2.4), the switches will be displayed as they are set in the software.  
3.2.4 RECONFIGURE SWITCH MODE  
To enter the Reconfigure Switch Mode, a terminal must be connected to Port A. When you type an  
ampersand (“&”) and then a pound sign (“#”), the A/S-2G will enter the Self-Diagnostics/Reconfigure  
Switch menu. Press the “2” key to enter the Reconfigure Switch Mode. The position of SW2, Switch  
#4 (for self-diagnostic testing) does not affect this operation.  
The setting for SW3-l (SW3, switch #1) will be displayed. To select the other option for SW3-l, press  
“T” (must be upper case). As long as “T” is pressed, the A/S-2G will toggle” between or among your  
options. The option will be chosen when you press “enter.” The next switch will then be displayed.  
After you have entered the last option, the A/S-2G will return to the main program.  
NOTE: If power is interrupted, the A/S-2G will use the manual configurations of SW1, SW2, and SW3  
when power is restored. The switch options chosen in the Reconfigure Switch Mode must be reentered.  
3.2.5 RS-232 PASS-THROUGH OPTIONS  
On the A/S-2G’s printed circuit board are three sets of double pass-through jumpers: DSR, DTR,  
and CD. You can have any, or all, of these signals pass-thru from one port to the other without being  
regulated by the A/S-2G.  
The DSR double jumper is located just below C7 on the circuit board. For normal operation  
(A/S-2G signal control), place the jumper over the center and left posts. For pass-through, position  
the jumper over the center and right posts.  
The DTR double jumper is located just below and slightly to the right of U28 on the circuit board.  
For normal operation (A/S-2G signal control), place the jumper over the center and left posts.  
For pass-through, position the jumper over the center and right posts.  
The CD double jumper is located between U20 and U24 on the circuit board. For normal operation  
(A/S-2G signal control), place the jumper over the center and upper posts. For pass-through, position  
the jumper over the center and lower posts.  
3.2.6 RESET OPTIONS  
You can configure the A/S-2G to reset automat-ically on the occurrence of Ring Indicate (RI) on either  
port or the loss of Data Set Ready (DSR) on Port A and/or Port B. These jumpers are located on the  
upper left of the circuit board, just below U7. Any, or all, of these jumpers may be selected. All of the  
reset options are disabled as shipped from the factory—the jumper is over the center and right posts.  
To enable one of these reset options, move the appropriate jumper over the left and center posts.  
3.3 PREPARING THE A/S-2G FOR CONNECTION TO AN ASYNCHRONOUS DEVICE  
The asynchronous port (Port A) is designed to connect to an asynchronous modem, terminal, or CPU.  
Set the switches, shunts, and jumpers as described below, then plug a male RS-232 connector into the  
A/S-2G’s female receptacle. Sex-change adapters, connectors, and cable are available if you need them.  
3.3.1 DATA TERMINAL READY (DTR) SIGNAL OPTIONS  
The asynchronous port DTR option control is a jumper labeled DTR A. It is located between U23  
and U24 on the circuit board. (See Figure 5-2 on page 28.) Placing the jumper over ON maintains a  
constant high signal on DTR. Placing this jumper to CNT allows the A/S-2G to control data flow based  
on the position of SW3, Switch #7.  
10  
 
CHAPTER 3: Installation  
If SW3, Switch #7 is ON, the A/S-2G will drop DTR when only 32 character spaces remain in the buffer.  
The A/S-2G will reassert DTR as soon as there are at least 33 character spaces available. For most  
applications, it is best to configure SW3, Switch #7 ON.  
If SW3, Switch #7 is OFF, the A/S-2G does not use DTR to control the buffer. Instead, the A/S-2G  
will issue either an X-ON or X-OFF to control data flow.  
3.3.2 CLEAR TO SEND (CTS) SIGNAL OPTIONS  
The asynchronous port CTS option control is a jumper labeled CTS A. It is located between U18 and  
U22 on the circuit board. (See Figure 5-2 on page 28.) Placing the jumper over ON maintains a  
constant high signal on CTS. Placing this jumper to CNT allows the A/S-2G to control data flow.  
When CTS is dropped by the device connected to the A/S-2G’s asynchronous port, the A/S-2G will hold  
whatever it has in its buffer and stop transmission until CTS is raised again. When the asynchronous  
port is configured as DCE (see Section 3.3.4), it is best to have the CTS A jumper positioned over ON.  
3.3.3 BAUD RATE OPTIONS  
SW1, switches #1 through #4 (See Figure 5-2 on page 28) control the Port A Baud Rate. Set these four  
switches so that the baud rate of the A/S-2G matches the baud rate of the modem, terminal, or CPU that  
you will be connecting to the asynchronous port. Refer to Table 3-1, Port A (Asynchronous) Baud Rate,  
to determine the position of each switch.  
NOTE  
The baud rate of the asynchronous port (Port A) cannot be set externally. Do not use the EXT setting for Port A.  
3.3.4 MODEM OR DIRECT-TO-TERMINAL CONNECTION  
When connecting the A/S-2G’s asynchronous port to a modem or external Asynchronous Modem  
Eliminator, the A/S-2G should be made to appear as DTE (Data Terminal Equipment).  
When connecting the A/S-2G’s asynchronous port directly to a terminal or CPU, the A/S-2G should  
be made to appear as DCE (Data Communications Equipment).  
To configure this interface correctly, place the DIP Shunt (which resembles a PROM) into the correct  
socket. There are two DIP Shunts—one for the asynchronous port and one for the synchronous port.  
Only one of these configurations—DTE or DCE— may be selected for each port at any given time. The DIP Shunt  
for the asynchronous port (Port A) should go on U27 or U28. (Refer to the printed circuit board  
layout, Figure 5-2, on page 28.) To remove or replace a DIP Shunt, follow the instructions for installing  
and replacing PROMs, Section 5.2, on page 24.  
PORT A (Asynchronous) BAUD RATE  
Rate  
1
2
3
4
Rate  
1
2
3
4
EXT (Invalid) OFF  
OFF  
OFF  
OFF  
OFF  
ON  
ON  
ON  
ON  
OFF  
OFF  
ON  
OFF  
ON  
OFF  
ON  
OFF  
ON  
OFF  
ON  
1800  
2000  
2400  
4800  
7200  
9600  
19200  
ON  
ON  
ON  
ON  
ON  
ON  
ON  
OFF  
OFF  
OFF  
ON  
ON  
ON  
OFF  
OFF  
ON  
OFF  
OFF  
ON  
OFF  
ON  
OFF  
OFF  
ON  
75  
OFF  
OFF  
OFF  
OFF  
OFF  
OFF  
OFF  
110  
134.5  
150  
300  
600  
1200  
ON  
OFF  
OFF  
ON  
OFF  
ON  
ON  
ON  
ON  
Table 3-1. Port A (Asynchronous) Baud Rates.  
11  
 
PROTOCOL CONVERTER A/S-2G  
3.3.5 CARRIER OPTIONS  
If the carrier detect signal is to be driven by the A/S-2G configuration (DCE), the jumper labeled CAR A  
ENB must be installed. CAR A ENB is located below U20. Refer to the printed circuit board, Figure 5-2,  
on page 28.  
The carrier control jumper, CARR A, in between U18 and U19 on the circuit board (See Figure 5-2 on  
page 28) should be set as follows:  
(a) continuous carrier—place the jumper over the ON position.  
(b) switched carrier equal to the RTS signal from the A/S-2G—place the jumper over the CNT position.  
If the A/S-2G asynchronous port is configured as DCE, place a jumper over CAR A ENB and place the  
CARR A jumper over ON.  
3.3.6 CABLE REQUIREMENT  
Use an RS-232 cable which is pinned straight through, i.e. 1 to 1, 2 to 2, 3 to 3, etc., to connect the A/S-  
2G’s asynchronous port to the modem, terminal, or CPU. Leads 1 through 8 and 20 are required (see  
Section 5.3 on page 25).  
3.4 PREPARING THE A/S-2G FOR CONNECTION TO A SYNCHRONOUS DEVICE  
The synchronous port (Port B) is designed to connect to a synchronous modem, modem eliminator, or  
terminal. Set the switches, shunts, and jumpers as described below, then plug a male RS-232 connector  
into the A/S-2G’s female receptacle. Sex-change adapters, connectors, and cable are available if you  
need them.  
PORT B (Synchronous) BAUD RATE  
Rate  
5
6
7
8
Rate  
5
6
7
8
EXT  
75  
OFF  
OFF  
OFF  
OFF  
OFF  
OFF  
OFF  
OFF  
OFF  
OFF  
OFF  
OFF  
ON  
ON  
ON  
ON  
OFF  
OFF  
ON  
OFF  
ON  
OFF  
ON  
OFF  
ON  
OFF  
ON  
1800  
2000  
2400  
4800  
7200  
9600  
19200  
ON  
ON  
ON  
ON  
ON  
ON  
ON  
OFF  
OFF  
OFF  
ON  
ON  
ON  
OFF  
OFF  
ON  
OFF  
OFF  
ON  
OFF  
ON  
OFF  
OFF  
ON  
110  
134.5  
150  
300  
600  
1200  
ON  
OFF  
OFF  
ON  
OFF  
ON  
ON  
ON  
ON  
Table 3-2. Port B (Synchronous) Baud Rates.  
3.4.1 DATA TERMINAL READY (DTR) SIGNAL OPTIONS  
The synchronous port DTR option control is a jumper labeled DTR B. It is just under U26 on the  
circuit board. (See Figure 5-2 on page 28.) Placing the jumper over ON maintains a constant high  
signal on DTR. When this jumper is placed over CNT, the A/S-2G will drop DTR during a reset or  
after receipt of a DLE EOT sequence from either the synchronous or the asynchronous port.  
For most installations, position the jumper over ON.  
3.4.2 CLEAR TO SEND (CTS) SIGNAL OPTIONS  
The synchronous port CTS option control is a jumper labeled CTS B. It is located between U21 and  
U25 on the circuit board. (See Figure 5-2 on page 28.) Placing the jumper over ON maintains a  
constant high signal on CTS. When this jumper is placed over CNT, the A/S-2G will raise RTS when  
12  
 
CHAPTER 3: Installation  
there is data to be transmitted. Once the A/S-2G receives CTS from the attached device, it will transmit  
the data. When the synchronous port (Port B) is configured as DTE, the CTS B jumper must be placed  
over the CNT position. Place the CTS B jumper over the CNT position when Port B is configured as  
DCE.  
3.4.3 BAUD RATE OPTIONS  
For externally provided synchronous clocking, the baud rate for the synchronous communication line  
is determined by the modem or modem eliminator. To select External Clock on Port B, all switches for  
Port B Baud Rate (SW1, Switches #5 through #8) must be in the OFF position.  
When Transmit and Receive Clock are optioned for INTERNAL, set the four switches so that the baud  
rate of the A/S-2G matches the baud rate of the external synchronous device. Refer to  
Table 3-2, Port B (Synchronous) Baud Rates, to determine the position of each switch.  
3.4.4 MODEM OR DIRECT-TO-TERMINAL CONNECTION  
When connecting the A/S-2G’s synchronous port to a modem or external Synchronous Modem  
Eliminator, the A/S-2G should be made to appear as DTE (Data Terminal Equipment).  
When connecting the A/S-2G’s synchronous port directly to a terminal or CPU, the A/S-2G should  
be made to appear as DCE (Data Communications Equipment).  
To configure this interface correctly, place the DIP Shunt (which resembles a PROM) into the correct  
socket. There are two DIP Shunts—one for the asynchronous port and one for the synchronous port.  
Only one of these configurations—DTE or DCE— may be selected for each port at any given time. The DIP Shunt  
for the synchronous port (Port B) should go on U29 or U30. Refer to the circuit board layout (Figure  
5-2 on page 28). To remove or replace a DIP Shunt, follow the instructions for installing and replacing  
PROMs, Section 5.2, on page 24.  
3.4.5 EXTERNAL OR INTERNAL CLOCKING OPTION  
The Receive and Transmit Clock options are controlled by two EXT B jumpers and two SME B jumpers.  
The EXT B jumpers are located near U25. The SME B jumpers are located just below U28.  
(Refer to the printed circuit board, Figure 5-2, on page 28.) The Receive and Transmit Clock  
jumpers must be selected to agree with the synchronous port DIP Shunt configuration as DTE or DCE.  
When the synchronous port has been configured as DTE, Transmit and Receive Clock must be optioned  
for EXTERNAL. Install both EXT B jumpers. Remove both SME B jumpers. Port B Baud Rate Switches  
(SW1, Switches #5 to #8) must all be in the OFF position.  
When the synchronous port has been configured as DCE, Transmit and Receive Clock must be optioned  
for INTERNAL. Remove both EXT B jumpers. Install both SME B jumpers. Port B Baud Rate switches  
(SW1, Switches #5 to #8) must then be set to match the synchronous baud rate of your external device.  
3.4.6 CARRIER OPTIONS  
If the Carrier Detect signal is to be driven by the A/S-2G configuration (DCE), the jumper labeled CAR  
B ENB must be installed. CAR B ENB is located next to U19. Refer to the printed circuit board, Figure  
5-2, on page 28.  
The carrier control jumper, CARR B, is located in between U18 and U19 on the circuit board (See  
Figure 5-2 on page 28). For most applications, the jumper should be placed over the CNT position.  
3.4.7 CABLE REQUIREMENT  
Use an RS-232 cable which is pinned straight through, i.e. 1 to 1, 2 to 2, 3 to 3, etc., to connect the  
A/S-2G’s synchronous port to a modem, modem eliminator, or terminal. Leads 1 through 8, 15, 17, 20,  
and 22 are required (see Section 5.3 on page 25).  
13  
 
PROTOCOL CONVERTER A/S-2G  
3.4.8 COMMAND PASS-THRU  
To use the command pass-thru feature, the command must be preceded by &% and terminated by &%.  
Example: &%-Command-&%  
Commands consist of character pairs. Each pair must represent a valid Hexidecimal value (i.e. zero  
through 9 or A through F). Example: To send an escape sequence to an attached ASCII device, such as  
“ESC A,” the following EBCDIC string must be sent to the A/S-2G: &%lB41&%.  
14  
 
CHAPTER 4: Operation  
4.0 Operation  
By its nature, a protocol converter must operate differently in each direction, since it is communicating  
with separate devices. Therefore, its operation will be discussed separately for asynchronous to  
synchronous operation and for synchronous to asynchronous.  
4.1 ASYNCHRONOUS DEVICE TO SYNCHRONOUS DEVICE  
4.1.1 LINE CONTROL  
When the A/S-2G is initially connected to an AC power source or reset, the asynchronous device can  
transmit data.  
When the synchronous side has control of the line, a turnaround cannot occur until an “End of  
Transmission” character has been entered from the controlling device. This character will be an EOT  
(EBCDIC 37 Hex) on the synchronous side.  
4.1.2 ASYNCHRONOUS INPUT DATA FORMAT  
The asynchronous side of the A/S-2G is programmed to accept asynchronous data within the following  
parameters:  
1 start bit  
7 data bits  
1 parity bit (any parity is accepted, but ignored. Parity is user-selectable by SW2, Switches #7 and #8.)  
1 or 2 stop bits (user-selectable with SW3, Switch #8)  
Half or full duplex (user-selectable with SW2, Switch #3)  
75 to 9600 bps (user-selectable by SW1, Switches #1 through #4)  
ASCII code  
ASCII CHARACTERS TRANSLATED TO EBCDIC  
ASCII  
to  
EBCDIC  
Control D  
1B (ASCII Hex)  
EOT (AA AA 32 32 32 32 37 FF)  
ESC (EBCDIC) (Hex 27)  
NL (New Line) (EBCDIC 15 Hex)  
CR (when SW3, Switch #3 is OFF)  
Table 4-1. ASCII characters translated to EBCDIC.  
4.1.3 DATA CONVERSION  
The A/S-2G converts Asynchronous ASCII data byte-for-byte to EBCDIC equivalents, blocks it  
appropriately and wraps it in the applicable protocol envelope. The only characters not converted  
byte-for-byte are listed in Tables 4-1 and 4-2.  
4.1.4 RECORD AND BLOCK SIZE  
In preparing asynchronous data for communi-cation to a synchronous device, the A/S-2G groups  
characters according to the block size selected (SW2, Switches #5 and #6).  
In accordance with 2770 and 2780 protocols, the A/S-2G adds an IUS (Hex 1F) followed by 2 block  
check characters (which are subsequently stripped by the EBCDIC device) after each 80 characters until  
a CR is received. The CR signifies the end of a block. If SW3, Switch #5 is OFF, the A/S-2G will fill the  
block with spaces until it reaches the block size specified by SW3, Switches 5 and 6. If SW3, Switch #5  
is ON, the block will end immediately after the CR.  
15  
 
PROTOCOL CONVERTER A/S-2G  
ASCII CHARACTERS NOT TRANSLATED TO EBCDIC  
CR (Carriage Return) when SW3, Switch #3 is ON, LF (Line Feed), Control characters are not passed.  
Character  
NUL  
Hex  
00  
01  
02  
03  
04  
05  
Character  
ACK  
Hex  
06  
10  
15  
16  
17  
1F  
SOH  
STX  
ETX  
EOT  
DLE  
NAK  
SYN  
ETB  
ENQ  
US  
Table 4-2. ASCII characters not translated to EBCDIC.  
In 3741 protocol, each block contains only one record. If SW3, Switch #5 is OFF, the A/S-2G will fill  
the block with spaces until it reaches 128 characters . If SW3, Switch #5 is ON, the block will end  
immediately after CR.  
NOTE:  
• If SW3, Switch #3 is OFF, then one character of the total count must be allotted to the CR. The CR  
will be translated into EBCDIC as a NL (New Line). Thus, if block size is specified as 80 characters,  
79 characters plus the CR would make a full 80 character record. Entering 80-characters and a CR  
would cause 2 records to be sent: one with the 80 characters; the second with the NL character and,  
if SW3, Switch #5 is OFF, 79 spaces.  
• When SW3, Switch #3 is ON, the A/S-2G will delete CR from the character count and send no  
representation of the CR with the EBCDIC data.  
4.1.5 USE OF CARRIAGE RETURN  
(A) 2770/2780 MODE  
Data from the asynchronous device is buffered (stored in RAM) until a CR (ASCII 0D Hex) is entered.  
If the A/S-2G receives asynchronous characters up to the selected block size without receiving a CR  
character, the A/S-2G will add an IUS character and a 2-byte CRC sequence to the block.  
When the A/S-2G receives a CR, the A/S-2G sends any buffered data to the synchronous device with  
an ETB (EBCDIC Hex 26).  
The last block of asynchronous data must end with a “Control D” (ASCII Hex 04). The A/S-2G will  
send the block, adding with an ETX (EBCDIC Hex 03). After receiving a positive acknowledgement,  
the A/S-2G sends an EOT.  
(B) 3741/3780 MODE  
Data from the asynchronous device is buffered until a CR (ASCII 0D Hex) is entered. When the  
A/S-2G receives a CR, the A/S-2G inserts an IRS (EBCDIC 1E Hex). Data will continue to accumulate  
until the selected block size is exceeded. At this point, the A/S-2G sends the full block of data.  
The last block of asynchronous data must end with a “Control D” (ASCII Hex 04). The A/S-2G will  
send the block, adding with an ETX (EBCDIC Hex 03). After receiving a positive acknowledgement,  
the A/S-2G sends an EOT.  
4.1.6 FLOW CONTROL  
The input buffer (RAM) is capable of storing up to 1720 characters. The asynchronous device can  
continuously send data to the A/S-2G if RAM is available and the character string contains a CR code  
before the buffer fills. (However, the maximum block size that is acceptable to the synchronous device  
must be considered.)  
16  
 
CHAPTER 4: Operation  
If SW3, Switch #7 is OFF, the A/S-2G will send an X-OFF (ASCII DC3, 13 Hex) to the asynchronous device  
when RAM reaches a nearly-full state. This prevents data from being lost due to a buffer overrun. When  
RAM space is available, the A/S-2G will send an X-ON (ASCII DC1, 11 Hex) to resume transmission.  
Alternatively, if SW3, Switch #7 is ON, the A/S-2G will lower the DTR (Pin 20) when RAM reaches a  
nearly-full state. When RAM space is available, the A/S-2G will again raise DTR to resume transmission.  
4.1.7 PRESENTATION OF DATA FROM A/S-2G TO SYNCHRONOUS DEVICE  
When an asynchronous device begins transmission to the A/S-2G and the A/S-2G has enough data for  
a block, the A/S-2G bids for the synchronous line and proceeds in standard bisynchronous protocol.  
See the Data Flow Diagrams on pages 15 through 19.  
NOTE  
Bracketed sections indicate a selectable option. Arrows indicate the direction of data flow.  
4.1.8 VERIFICATION OF DATA RECEPTION  
When operating in full duplex mode from the asynchronous side, SW3, Switches #1 and #2 permit visual  
assurance of accurate and complete transmission. When SW3, Switch #1 is ON, the A/S-2G will  
immediately echo back all the data it receives from the asynchronous device. When SW3, Switch #2 is  
ON, the A/S-2G will send a CR, LF, and EOT to the asynchronous device after a complete transmission  
and a line turn-around have successfully been completed.  
4.1.9 LINE TURNAROUND  
The final record transmitted from the asynchronous side must be terminated with a “Control D” (ASCII  
04 Hex) character. This notifies the A/S-2G that the asynchronous device has completed its entry and is  
relinquishing the line. After all data is sent, the A/S-2G will send an EOT sequence to the synchronous  
side.  
Data Flow — A/S-2G to Synchronous Device  
Bisynchronous Device  
A/S-2G Converter  
Asynchronous Device  
Characters up to maximum  
BSC Block size (2770, 2780,  
3780) or one 128 character  
record (3741) terminated by  
CR (0D Hex) = Block A of  
data received in start/stop  
format  
(Echo all but CR LF)  
ENQ  
Line Bid  
AA AA 32 32 32 32 2D FF FF  
ACK 0  
Positive Acknowledgment—  
Even AA AA 32 32 32 32 10  
70 FF FF  
Send block A  
17  
 
PROTOCOL CONVERTER A/S-2G  
Data Flow — A/S-2G to Synchronous Device  
Bisynchronous Device  
A/S-2G Converter  
Asynchronous Device  
IF 2270 - 2780  
AA AA 32 32 32 32 02  
(text up to 80 characters),  
IF, BCC1, BCC2; etc. (last  
record 26, BCC1, BCC2, FF  
FF  
IF 3780  
AA AA 32 32 32 32 02  
(text up to 80* characters  
with records separated by  
1E, last record in block 1E,  
26, BCC1, BCC2, FF FF  
IF 3741  
AA AA 32 32 32 32 02  
(up to 128 characters), 26,  
BCC1, BCC2, FF FF  
ACK 1  
Positive Acknowledgment—  
Odd AA AA 32 32 32 32 10  
61 FF FF  
(Echo CR LF)  
Block B of data  
(Echo all but CR LF)  
Send block B  
ACK 0  
(Echo CR LF)  
Block C of data  
(Echo all but CR LF)  
Block of D of data begins  
*Assumes block size of 80 is selected.  
18  
 
CHAPTER 4: Operation  
Data Flow — A/S-2G to Synchronous Device  
Bisynchronous Device  
A/S-2G Converter  
Asynchronous Device  
If A/S-2G buffer is nearly full when asynchronous device is transmitting:  
X-OFF  
Holds up transmission while  
buffer clears DC3 (ASCII 13  
Hex) or drop DTR CTS or  
user-specified lead  
Send block C  
Frees up buffer space.  
ACK 1  
(Echo CR LF)  
X-ON  
Allow resumption of  
transmission DC1 (ASCII 11  
Hex) or raise DTR  
Complete block D  
If data not properly received by synchronous device or  
synchronous device has no WAK capability and buffer is full:  
Send block D  
NAK  
Negative Acknowledgment  
AA AA 32 32 32 32 3D FF FF  
Resend block D  
ACK 0  
If synchronous device has WAK capability and buffer is full:  
Send block E  
(Echo all but CR LF)  
Send block E  
2-second interval  
WAK  
AA AA 32 32 32 32 6B FF FF  
19  
 
PROTOCOL CONVERTER A/S-2G  
Data Flow — A/S-2G to Synchronous Device  
Bisynchronous Device  
A/S-2G Converter  
Asynchronous Device  
(Echo CR LF)  
Send block F  
(Echo all but CR LF)  
ENQ  
2-second interval  
WAK  
WAK resets ENQ counter  
ENQ  
Sync device buffer space available  
ACK 1  
ACK 0  
Send block F  
(Echo CR LF)  
If data not yet available from asynchronous device:  
If over 3-second interval  
AA 32 32 32 32 02 2D FF FF  
TTD  
NAK  
AA AA 32 32 32 32 3D FF FF  
Line release or turnaround:  
Send block G,  
(end with EOT Hex 04)  
(Echo all but CR LF EOT)  
Send block G  
20  
 
CHAPTER 4: Operation  
Data Flow — A/S-2G to Synchronous Device  
Bisynchronous Device  
A/S-2G Converter  
Asynchronous Device  
IF 2270 - 2780  
AA AA 32 32 32 32 02  
(text up to 80 characters),  
IF, BCC1, BCC2; etc. (last  
record 03, BCC1, BCC2, FF  
FF  
IF 3780  
AA AA 32 32 32 32 02  
(text up to 80* characters  
with records separated by  
1E, last record in block 1E,  
03, BCC1, BCC2, FF FF  
IF 3741  
AA AA 32 32 32 32 02  
(up to 128 characters), 03,  
BCC1, BCC2, FF FF  
ACK 1  
Send EOT  
AA AA 32 32 32 32 37 FF FF  
(Echo CR LF EOT)  
Line is now idle  
*Assumes block size of 80 is selected.  
21  
 
PROTOCOL CONVERTER A/S-2G  
4.2 SYNCHRONOUS DEVICE TO ASYNCHRONOUS DEVICE  
4.2.1 LINE CONTROL  
When the A/S-2G is initially connected to an AC power source or reset, the synchronous device can gain  
control of the line by sending an ENQ.  
When the asynchronous side has control of the line, a turnaround cannot occur until an “End of  
Transmission” character has been entered from the controlling device. This character will be a “Control  
D” (ASCII 04 Hex) on the asynchronous side.  
4.2.2 SYNCHRONOUS INPUT DATA FORMAT  
The synchronous side of the A/S-2G is programmed to receive data whose format is completely  
specified by the protocol in use (2770, 2780, 3741, or 3780). It will be in EBCDIC code at a data rate of  
up to 9600 bps.  
4.2.3 DATA CONVERSION  
The A/S-2G converts all synchronous EBCDIC data characters byte-for-byte to ASCII characters. The  
A/S-2G strips synchronization and protocol characters and adds asynchronous start and stop bits. The  
only exceptions in translating EBCDIC characters to ASCII Characters are listed in Tables 4-3 and 4-4  
below.  
4.2.4 FLOW CONTROL  
The input buffer (RAM) is capable of storing up to a maximum of 1720 characters. The synchronous  
device can continuously send data to the A/S-2G so long as RAM is available. When a nearly-full state is  
reached (as determined by the selected block size), the A/S-2G will send a WAK (Wait  
Acknowledgement) to halt synchronous transmission until memory is available.  
EBCDIC CHARACTERS TRANSLATED TO ASCII  
EBCDIC  
to  
ASCII  
NL (New Line) (Hex 15)  
EE or 27  
CR LF  
ESC  
ESC S  
ESC T  
ESC A  
CR LF CR LF  
CR LF CR LF CR LF  
FF  
ESC M  
all other escapes  
CR, Suppress LF  
CR LF  
Table 4-3. EBCDIC characters translated to ASCII.  
4.2.5 VERIFICATION OF DATA RECEPTION  
The A/S-2G uses the standard synchronous pro-tocol, ensuring data receipt and integrity through the  
standard ACK (Positive Acknowledgement), NAK (Negative Acknowledgement), and CRC-16 (cyclic  
redundancy check 16th degree polynominal structures).  
4.2.6 LINE TURNAROUND  
The final transmission from the synchronous side will be the EOT sequence (EBCDIC Hex 37). This  
releases the line and allows the A/S-2G to enter an idle mode wherein it will accept a line bid from  
either side.  
22  
 
CHAPTER 4: Operation  
Should the A/S-2G receive a DLE EOT (disconnect), the A/S-2G will cycle the synchro-nous DTR lead  
off for 2 seconds. This action will disconnect a phone line if the DTR B jumper is set for CNT.  
NOTE  
The A/S-2G will cycle the synchronous DTR lead off for 2 seconds whether the DLE EOT sequence comes from  
the synchronous or asynchronous side.  
EBCDIC CHARACTERS STRIPPED  
Character  
Hex  
Character  
Hex  
NUL  
SOH  
STX  
ETX  
EOT  
ENQ  
00  
01  
02  
03  
37  
2D  
ACK  
DLE  
NAK  
SYN  
ETB  
2E  
10  
3D  
32  
26  
Table 4-4. EBCDIC characters stripped.  
23  
 
PROTOCOL CONVERTER A/S-2G  
Data Flow — A/S-2G to Asynchronous Device  
Bisynchronous Device  
A/S-2G Converter  
Asynchronous Device  
ENQ  
ACK 0  
Send data block A  
ACK 1  
Send block A  
Unformatted mode—  
successive characters  
(including spaces) appear  
one after another as sent  
If A/S-2G buffer is nearly full when synchronous device is transmitting:  
Send data block B  
2-second interval  
WAK  
ENQ  
2-second interval  
WAK  
Send block B  
ENQ  
WAK resets ENQ counter with  
respect to ENQ time out  
ACK 0 (when  
buffer  
available)  
Send data block C  
ACK 1  
Send block C  
24  
 
CHAPTER 4: Operation  
Data Flow — A/S-2G to Asynchronous Device  
Bisynchronous Device  
A/S-2G Converter  
Asynchronous Device  
Send data block D  
NAK  
Send data block D  
ACK 0  
when available  
Send block D  
If data not properly received by A/S-2G:  
Send data block E  
Retransmit block E  
NAK  
ACK 1 (when  
correctly  
received)  
Send block E  
If data not yet available from synchronous device  
while synchronous line to A/S-2G is engaged:  
2-second interval from previous ACK  
TTD  
TTD  
NAK  
2-second interval  
NAK  
Continues until data available  
25  
 
PROTOCOL CONVERTER A/S-2G  
Data Flow — A/S-2G to Asynchronous Device  
Bisynchronous Device  
A/S-2G Converter  
Asynchronous Device  
Line release or turnaround  
Send data block F  
(last block)  
ACK 0  
Send block F  
EOT  
Send C R LF EOT  
to asynchronous  
device if SW3,  
switch #2 is ON  
Line can now be turned around or A/S-2G in idle mode  
26  
 
CHAPTER 5: Conversions and Connections  
5.0 Conversions and Connections  
5.1 TRANSPARENCY MODE OF OPERATION  
With a special transparency PROM installed, the A/S-2G will communicate with a host system in IBM  
binary synchronous transparent mode. To special-order the transparency PROM, please call technical  
support.  
In transparent mode, no character translations are performed in either direction, allowing transmission  
of binary file such as raw data or program object files.  
In accordance with IBM specifications, each data block is bracketed with a protocol envelope consisting  
of a DLE STX (EBCDIC 10 Hex, 02 Hex) at the beginning and DLE ETB (EBCDIC 10 Hex, 26 Hex) at  
the end. Should a DLE (10 Hex) occur within the data block, a second DLE (10 Hex) is inserted by the  
sending device to eliminate the possibility of a legal DLE sequence occurring by chance in the data.  
The A/S-2G software automatically inserts or strips the extra DLE (10 Hex) when necessary.  
Transparency mode always sends fixed length blocks. Block size is selected with SW2, Switches #5 and  
#6. The variable/fixed switch only pertains to the last (partial) block received from the asynchronous  
port. The A/S-2G software detects the end of incoming asynchronous data in one of two ways:  
1. Receipt of an ASCII ESC Control-D sequence (1B Hex, 04 Hex), with no other data  
following for one second.  
2
No asynchronous data received for a period of twelve seconds.  
When one of these conditions occurs, the A/S-2G will transmit the last block terminated with DLE ETX.  
Upon acknowledgement of this last block, an EOT sequence is sent.  
The transparency mode software will accept data blocks of any size (assuming no memory overflow)  
and will handle variable length or fixed blocks.  
5.2 INSTALLING OR REPLACING PROMS  
1. Unplug the A/S-2G from the AC power.  
2. Remove the cover of the A/S-2G.  
3. To locate the PROM, see Figure 5-2 on page 28. The PROM is located on U11, between U10 and  
U12.  
4. Using a PROM extraction tool or a small screwdriver, pry the PROM out of the socket until it is loose.  
Then, slide the tool or your fingers under the PROM and gently lift up. You must lift directly upward  
to avoid damaging the teeth of the PROM.  
5. Now insert your new PROM. It may require its pins to be pushed in a little. If so, use a table top  
to do this. This will ensure that the pins stay aligned.  
Caution  
Note the orientation of the indentation on one of the prom’s short ends—it must line up with the matching  
indentation on the socket into which it is inserted.  
27  
 
PROTOCOL CONVERTER A/S-2G  
5.3 RS-232 CABLE CHART  
RS-232C pins are defined as follows:  
1 = Chassis (or Frame or Protective) Ground  
2 = Transmit Data  
F-GND, C-GND, or P-GND  
TD or TXD  
3 = Receive Data  
RD or RXD  
4 = Request to Send  
RTS  
5 = Clear to Send  
CTS  
6 = Data Set Ready  
DSR  
7 = Signal Ground  
S-GND  
8 = Carrier Detect  
CD  
15 = Transmit Signal Element Timing (Clock)  
17 = Receive Signal Element Timing (Clock)  
20 = Data Terminal Ready  
22 = Ring Indicator  
T-CLK or TXCLK  
R-CLK or TXCLK  
DTR  
RI  
RS-232 Interface  
SIGNAL  
DESTINATION  
PIN  
NUMBER  
PIN  
NUMBER  
SIGNAL  
DESTINATION  
1
2
3
4
5
6
7
8
9
PROTECTIVE GROUND  
TRANSMITTED DATA  
RECEIVED DATA  
REQUEST TO SEND  
CLEAR TO SEND  
SECONDARY TRANSMITTED DATA 14  
DCE TRANSMITTER SIGNAL ELEMENT TIMING 15  
SECONDARY RECEIVED DATA 16  
RECEIVER SIGNAL ELEMENT TIMING 17  
18  
DATA SET READY  
SECONDARY REQUEST TO SEND 19  
DATA TERMINAL READY 20  
SIGNAL GROUND/COMMON RETURN  
RECEIVED LINE SIGNAL DETECTOR  
+VOLTAGE  
SIGNAL QUALITY DETECTOR 21  
RING INDICATOR 22  
DATA SIGNAL RATE SELECTOR 23  
DTE TRANSMITTER SIGNAL ELEMENT TIMING 24  
25  
10 -VOLTAGE  
11  
12 SECONDARY RECEIVED LINE SIGNAL DETECTOR  
13 SECONDARY CLEAR TO SEND  
Figure 5-1. The RS-232 Interface.  
28  
 
CHAPTER 5: Conversions and Connections  
5.4 CODE CONVERSIONS  
The conversions used in the standard 2770, 2780, 3741, and 3780 PROMs are shown in the following  
charts. Your PROM can be customized. Please call Technical Support if you have particular translation  
requirements.  
Abbreviations:  
Dir. = Direction of Conversion  
NP = No pass (no translation in either direction)  
Character  
or  
Character  
or  
ASCII  
EBCDIC  
Hex  
ASCII  
EBCDIC  
Hex  
Graphic  
Hex Dir.  
Comments  
Graphic  
Hex Dir.  
Comments  
29  
35  
1F  
2C  
NUL  
SOH  
STX  
ETX  
EOT  
ENQ  
ACK  
BEL  
BS  
00  
01  
02  
03  
04  
05  
06  
07  
08  
NP  
00  
01  
02  
03  
37  
2D  
2E  
2F  
16  
36  
05  
39  
25  
OB  
OC  
0A  
3A  
OD  
15  
06  
1E  
33  
OE  
OF  
RS  
US  
1E  
1F  
IRS EBCDIC  
SPACE  
20  
40  
41  
E1  
5A  
7F  
7B  
5B  
6C  
50  
7D  
4D  
5D  
5C  
4E  
6B  
60  
CA  
4B  
61  
Required Space  
Numeric Space  
EBCDIC DP  
!
"
#
$
%
&
'
(
)
*
+
,
21  
22  
23  
24  
25  
26  
27  
28  
29  
2A  
2B  
2C  
2D  
Numeric BS  
HT  
09  
Required Tab  
LF  
VT  
FF  
0A  
0B  
0C  
Repeat WP  
Required Page End  
CR  
CR  
CR  
CR  
CR  
SO  
SI  
0D  
Required CR  
Index Return  
-
SYL. Hyphen  
.
/
2E  
2F  
OE  
OF  
0
1
2
3
4
5
6
7
8
9
:
30  
31  
32  
33  
34  
35  
36  
37  
38  
39  
3A  
3B  
3C  
3D  
3E  
3F  
F0  
F1  
F2  
F3  
F4  
F5  
F6  
F7  
F8  
F9  
7A  
5E  
DLE  
DC1  
DC2  
DC3  
DC4  
NAK  
SYN  
ETB (EOB) 17  
CAN  
EM  
10  
11  
12  
13  
14  
15  
16  
10  
11  
12  
13  
3C  
3D  
32  
26  
18  
19  
3F  
27  
EE  
22  
1C  
1D  
NP  
NP  
18  
19  
1A  
1B  
SUB  
ESC  
;
=
?
7E  
6F  
1C  
1C  
1D  
FS  
GS  
29  
 
PROTOCOL CONVERTER A/S-2G  
Character  
or  
Character  
or  
ASCII  
EBCDIC  
Hex  
ASCII  
EBCDIC  
Hex  
Graphic  
Hex Dir.  
Comments  
Graphic  
Hex Dir.  
Comments  
@
A
B
C
D
E
F
G
H
I
J
K
L
M
N
O
40  
41  
42  
43  
44  
45  
46  
47  
48  
49  
4A  
4B  
4C  
4D  
4E  
4F  
7C  
C1  
C2  
C3  
C4  
C5  
C6  
C7  
C8  
C9  
D1  
D2  
D3  
D4  
D5  
D6  
o
6F  
96  
p
q
r
s
t
u
v
w
x
y
z
70  
71  
72  
73  
74  
75  
76  
77  
78  
79  
7A  
7B  
7B  
7C  
7D  
7D  
7E  
7F  
97  
98  
99  
A2  
A3  
A4  
A5  
A6  
A7  
A8  
A9  
C0  
8B  
6A  
D0  
9B  
A1  
07  
|
1/2 EBCDIC  
P
Q
R
S
T
U
V
W
X
Y
Z
50  
51  
52  
53  
54  
55  
56  
57  
58  
59  
5A  
5B  
5B  
5C  
5D  
5D  
5E  
5F  
D7  
D8  
D9  
E2  
E3  
E4  
E5  
E6  
E7  
E8  
E9  
4A  
AD  
E0  
4F  
BD  
5F  
6D  
DEL  
SPECIAL CONVERSIONS  
EBCDIC to ASCII  
Comments  
ESC A  
ESC M  
ESC S  
FF  
CR  
Suppress LF for underscore  
Two CR LF sequences  
CR LF  
CR LF  
^
- EBCDIC  
EBCDIC underscore  
ESC T  
CR LF  
CR LF  
CR LF  
Three CR LF sequences  
60  
60  
61  
62  
63  
64  
65  
66  
67  
68  
69  
6A  
6B  
6C  
6D  
6E  
79  
14  
81  
82  
83  
84  
85  
86  
87  
88  
89  
91  
92  
93  
94  
95  
Any other ESC CR LF  
sequence  
a
b
c
d
e
f
g
h
i
j
k
l
m
n
NL  
CR LF  
ASCII  
to  
EBCDIC Comments  
NL This occurs only when SW3,  
Switch #3 is OFF.  
CR  
30  
 
CHAPTER 5: Conversions and Connections  
UNASSIGNED EBCDIC CODE  
04  
08  
09  
17  
1A  
2B  
30  
31  
34  
38  
46  
47  
48  
49  
51  
58  
59  
62  
63  
64  
71  
72  
73  
74  
75  
8D  
8E  
8F  
90  
9A  
AB  
AC  
AE  
AF  
B0  
B7  
B8  
B9  
BA  
BB  
CE  
CF  
DA  
DB  
DC  
ED  
EF  
FA  
FB  
FC  
20  
21  
23  
24  
28  
2A  
3B  
3E  
42  
43  
44  
45  
52  
53  
54  
55  
56  
57  
65  
66  
67  
68  
69  
70  
76  
77  
78  
80  
8A  
8C  
9C  
9D  
9E  
9F  
A0  
AA  
B1  
B2  
B3  
B4  
B5  
B6  
BC  
BE  
BF  
CB  
CC  
CD  
DD  
DE  
DF  
EA  
EB  
EC  
FD  
FE  
FF  
5.5 PRINTED CIRCUIT BOARD LAYOUT  
EPROM  
Figure 5-2. Printed Board Circuit Layout.  
31  
 
© Copyright 1998. Black Box Corporation. All rights reserved.  
1000 Park Drive Lawrence, PA 15055-1018 724-746-5500  
Fax 724-746-0746  
 

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