Black Box IC026A-R2, IC026AE-R2 User Manual
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INFORMATION
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MARCH 1998
IC026A-R2
IC026AE-R2
RS-232↔IEEE 488
Interface Converter
TALK
LISTEN
SRQ
ERROR
POWER
2
RS-232↔IEEE 488 INTERFACE CONVERTER
EUROPEAN UNION DECLARATION OF CONFORMITY
To maintain safety, emission, and immunity standards of this declaration,
the following conditions must be met.
• Serial and IEEE cables must have a braided shield connected
circumferentially to their connectors’ metal shells.
• All cable screw locks must be tightened at both ends of the cable.
• The host computer must be properly grounded.
• Some inaccuracy is to be expected when I/O leads are exposed
to RF fields or transients.
• The operator must observe all safety cautions and operating conditions
specified in the documentation for all hardware used.
• The host computer, peripheral equipment, power sources, and expansion
hardware must be CE compliant.
• All power must be off to the device and externally connected equipment
before internal access to the device is permitted.
• An external power supply is provided with this product. Its input is 105
to 125 VAC or 210 to 250 VAC, 50-60 Hz, 10 VA maximum power draw.
Its 9-VDC output connects to the power input of the unit (marked 10VDC
MAX @ 500 mA).
• The RS-232/422 terminal is meant to be connected only to devices with
serial-communications-level signals. The IEEE 488 terminal is meant to be
used only with non-isolated IEEE 488 systems. The common mode voltage
(cable shell to earth) must be zero.
• Terminal Installation Category for CE Compliance is Category 1.
• Operating environment for CE compliance is: Indoor use at altitudes
below 2000 m, 0 to 40°C, 80% maximum RH up to 31°C decreasing
linearly 4%RH/°C to 40°C.
• Regarding DC power input: Please note that the power input is marked
10VDC MAX @ 600 mA. This is just something to check; check your
equipment’s power input labels for “600 mA” (or even 500 mA).
3
WARNING!
Noted conditions pertain to potential safety hazards. When you see a
WARNING!, CAUTION!, or IMPORTANT! note, carefully read the
information and be alert to the possibility of personal injury.
Failure to follow these directives voids emission and immunity compliance.
TRADEMARKS USED IN THIS MANUAL
AT
®
, IBM®, and PS/2®are registered trademarks, and PC/XT is a trademark,
of IBM Corporation.
Macintosh®is a registered trademark of Apple Computer, Inc.
Hewlett-Packard
®
, HP®, and HP-GL®are registered trademarks of Hewlett-Packard.
AutoCAD
®
is a registered trademark of AUTODESK, Inc.
MacPlot
®
is a registered trademark of Microspot Ltd.
All applied-for and registered trademarks are the property of their respective owners.
4
RS-232↔IEEE 488 INTERFACE CONVERTER
FEDERAL COMMUNICATIONS COMMISSION
AND
INDUSTRY CANADA
RADIO FREQUENCY INTERFERENCE STATEMENTS
This equipment generates, uses, and can radiate radio frequency energy
and if not installed and used properly, that is, in strict accordance with the
manufacturer’s instructions, may cause interference to radio communication.
It has been tested and found to comply with the limits for a Class A computing
device in accordance with the specifications in Subpart J of Part 15 of FCC
rules, which are designed to provide reasonable protection against such
interference when the equipment is operated in a commercial environment.
Operation of this equipment in a residential area is likely to cause interference,
in which case the user at his own expense will be required to take whatever
measures may be necessary to correct the interference.
Changes or modifications not expressly approved by the party responsible
for compliance could void the user’s authority to operate the equipment.
This digital apparatus does not exceed the Class A limits for radio noise emission from
digital apparatus set out in the Radio Interference Regulation of Industry Canada.
Le présent appareil numérique n’émet pas de bruits radioélectriques dépassant les limites
applicables aux appareils numériques de classe A prescrites dans le Règlement sur le
brouillage radioélectrique publié par Industrie Canada.
5
NOM STATEMENT
NORMAS OFICIALES MEXICANAS (NOM)
ELECTRICAL SAFETY STATEMENT
INSTRUCCIONES DE SEGURIDAD
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.
6
RS-232↔IEEE 488 INTERFACE CONVERTER
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.
7
CONTENTS
Contents
Chapter Page
1. Specifications..................................................................................................10
2. Introduction ...................................................................................................12
2.1 Description ............................................................................................12
2.2 Abbreviations.........................................................................................13
3. Getting Started ...............................................................................................14
3.1 Inspection ..............................................................................................14
3.2 Configuration ........................................................................................14
3.3 Serial Port Settings ................................................................................16
3.3.1 Serial Baud Rate ........................................................................16
3.3.2 Serial Word Length (Data Bits)................................................18
3.3.3 Serial Stop Bits ...........................................................................18
3.3.4 Serial Parity ................................................................................19
3.3.5 Serial Echo .................................................................................19
3.3.6 Serial Handshake.......................................................................20
3.4 Selecting Terminator Substitution.......................................................21
3.4.1 Serial Terminator ......................................................................21
3.4.2 IEEE Bus Terminator ................................................................22
3.5 Selecting the Mode ...............................................................................22
3.6 Selecting the IEEE Address ..................................................................23
3.7 Feature Selections .................................................................................24
3.7.1 Controller Features ...................................................................24
3.7.2 Peripheral Features ...................................................................25
3.8 Serial Interface ......................................................................................25
3.8.1 RS-232/RS-422 Signal Level Selection .....................................26
3.8.2 Serial Signal Descriptions..........................................................26
3.8.3 Serial-Cable Wiring Diagrams...................................................29
3.9 General Operation................................................................................30
4. Controller Operation.....................................................................................32
4.1 Controller-Mode (Serial to IEEE) Operation .....................................32
4.2 Serial and IEEE Terminator Substitution............................................33
4.3 IEEE Address Selection.........................................................................34
8
RS-232↔IEEE 488 INTERFACE CONVERTER
Chapter Page
4.4 Talk-Back Features ................................................................................34
4.4.1 Talk-Back on Terminator..........................................................34
4.4.2 Talk-Back on Timeout...............................................................36
4.5 Plotter Applications...............................................................................38
4.6 Printer Applications ..............................................................................44
5. Peripheral Operation.....................................................................................45
5.1 Peripheral-Mode Operation .................................................................45
5.2 Serial and IEEE Input Buffers ..............................................................45
5.3 IEEE Data Transfers..............................................................................46
5.3.1 Blind Bus Data Transfers...........................................................46
5.3.2 Controlled Bus Data Transfers .................................................47
5.4 Serial-Poll Status-Byte Register .............................................................48
5.5 Use of Serial and Bus Terminators ......................................................50
5.6 IEEE 488 Bus Implementation.............................................................50
5.6.1 My Talk Address (MTA)............................................................51
5.6.2 My Listen Address (MLA) .........................................................51
5.6.3 Device Clear (DCL and SDC)...................................................51
5.6.4 Interface Clear (IFC).................................................................51
5.6.5 Serial Poll Enable (SPE)............................................................51
5.6.6 Serial Poll Disable (SPD) ..........................................................51
5.6.7 Unlisten (UNL) .........................................................................51
5.6.8 Untalk (UNT)............................................................................51
5.7 IEEE Address Selection.........................................................................52
6. IEEE 488 Primer.............................................................................................53
6.1 History....................................................................................................53
6.2 General Structure..................................................................................53
6.3 Send It To My Address..........................................................................55
6.4 Bus Management Lines.........................................................................56
6.4.1 Attention (ATN)........................................................................56
6.4.2 Interface Clear (IFC).................................................................56
6.4.3 Remote Enable (REN) ..............................................................56
6.4.4 End Or Identify (EOI) ..............................................................56
6.4.5 Service Request (SRQ) ..............................................................56
9
CONTENTS
Chapter Page
6.5 Handshake Lines...................................................................................57
6.5.1 Data Valid (DAV).......................................................................57
6.5.2 Not Ready For Data (NRFD) ....................................................57
6.5.3 Not Data Accepted (NDAC) .....................................................57
6.6 Data Lines ..............................................................................................58
6.7 Multiline Commands ............................................................................58
6.7.1 Go To Local (GTL) ...................................................................58
6.7.2 Listen Address Group (LAG)....................................................58
6.7.3 Unlisten (UNL) .........................................................................59
6.7.4 Talk Address Group (TAG) ......................................................59
6.7.5 Untalk (UNT)............................................................................59
6.7.6 Local Lockout (LLO)................................................................59
6.7.7 Device Clear (DCL)...................................................................59
6.7.8 Selected Device Clear (SDC) ....................................................59
6.7.9 Serial Poll Disable (SPD) ..........................................................59
6.7.10 Serial Poll Enable (SPE)..........................................................59
6.7.11 Group Execute Trigger (GET)...............................................59
6.7.12 Take Control (TCT)................................................................60
6.7.13 Secondary Command Group (SCG) ......................................60
6.7.14 Parallel Poll Configure (PPC).................................................60
6.7.15 Parallel Poll Unconfigure (PPU)............................................60
6.8 More on Service Requests.....................................................................60
6.8.1 Serial Poll ...................................................................................61
6.8.2 Parallel Poll ................................................................................61
7. Theory of Operation and Board Layout.......................................................62
7.1 Theory of Operation.............................................................................62
7.2 Board Layout .........................................................................................63
Appendix A: Sample Dumb-Terminal Program...............................................65
Appendix B: Character Codes and IEEE Multiline Messages .........................66
Index ...................................................................................................................68
10
RS-232↔IEEE 488 INTERFACE CONVERTER
IEEE-488 Interface
Implementation — C1, C2, C3, C4, and C28 controller subsets.
Serial to IEEE: SH1, AH1, T6, TE0, L4, LE0,
SR1, RL0, PP0, DC1, DT0, E1.
Terminators — Selectable CR, LF, LF-CR, and CR-LF
with EOI
Connector — Standard IEEE 488 connector with metric studs
Serial Interface
EIA RS-232C — AB, BA, BB, CA, CB
EIA RS-422A — Balanced voltage on TxD and RxD
Character Set — Asynchronous bit serial
Output Voltage — ±5 volts min. (RS-232C);
5 volts typical (RS-422A)
Input Voltage — ±3 volts min.; q15v max.
Baud Rate — Selectable 110, 300, 600, 1200, 1800, 2400,
3600, 4800, 7200, 9600, 19,200, and 57,600
Data Format — Selectable 7 or 8 data bits; 1 or 2 stop bits;
odd, even, mark, space, and no parity on
transmit
Duplex — Full with Echo/No Echo
Serial Control — Selectable CTS/RTS or XON/XOFF
Terminators — Selectable CR, LF, LF-CR, and CR-LF
Connector — 25-pin sub-D male, DCE configured
1. Specifications
11
General
Data Buffer — 32,000 characters dynamically allocated
Indicators — LEDs for IEEE Talk and Listen, Serial Send
and Receive, and Power
Power — 105-125V or 210-250V; 50-60 Hz, 10 VA max.
Size — 2.7"H x 5.5"W x 7.4"D (6.9 x 14 x 18.8 cm)
Weight — 3.6 lb. (1.6 kg)
Environment — 0 to 50°C; 0 to 70% R.H. to 35°C.
Linearly derate 3% R.H./degrees Centigrade
from 35 to 50°C
Controls — Power Switch (external), IEEE and Serial
parameter switches (internal). Jumper
selection of RS-232 or RS-422 operation
(internal)
Certification — FCC, CE
WARNING!
Do not use this interface outdoors. The interface is intended for indoor
use only. Using this equipment outdoors could result in equipment
failure, bodily injury, or death.
CAUTION
Do not connect AC line power directly to the RS-232↔IEEE 488 Interface
Converter. Direct AC connection will damage equipment.
CHAPTER 1: Specifications
12
RS-232↔IEEE 488 INTERFACE CONVERTER
2.1 Description
The RS-232↔488 Interface Converter provides transparent communication
from a serial computer to an IEEE 488 printer, plotter, or other device. It also
can be used to control a serial device, such as a printer or terminal, from an
IEEE 488 host computer.
As a serial-to-IEEE-488 converter, the interface converter receives data from
a serial host then automatically performs the bus sequences necessary to send
this data to the IEEE 488 device. If desired, data can be requested from the
IEEE 488 device and returned to the host.
As an IEEE 488 to serial converter the interface converter is a peripheral to
an IEEE 488 controller. Data received from the controller is sent to the serial
device, and the data received from the serial device is buffered for transmission to the IEEE 488 controller. The interface converter can inform
the host, by the serial poll-status byte, that it has received data from the
serial device.
2. Introduction
13
2.2 Abbreviations
The IEEE 488 abbreviations listed below are used throughout this manual.
addr n IEEE bus address “n”
ATN Attention line
CA Controller Active
CO Controller
CR Carriage Return
data Data String
DCL Device Clear
GET Group Execute Trigger
GTL Go To Local
LA Listener Active
LAG Listen Address Group
LF Line Feed
LLO Local Lock Out
MLA My Listen Address
MTA My Talk Address
PE Peripheral
PPC Parallel Poll Configure
PPU Parallel Poll Unconfigure
SC System Controller
SDC Selected Device Clear
SPD Serial Poll Disable
SPE Serial Poll Enable
SRQ Service Request
TA Talker Active
TAD Talker Address
TCT Take Control
term Terminator
UNL Unlisten
UNT Untalk
* Unasserted
CHAPTER 2: Introduction
14
RS-232↔IEEE 488 INTERFACE CONVERTER
3.1 Inspection
The interface converter was carefully inspected, both mechanically and
electrically, prior to shipment. When you receive it, carefully unpack all items
from the shipping carton and check for any obvious signs of damage that may
have occurred during shipment. Immediately report any damage found to the
shipping agent. Remember to retain all shipping materials in the event that
shipment back to the factory becomes necessary.
Every interface converter is shipped with the following:
• RS-232↔IEEE 488 Interface Converter
• This instruction manual
• Power supply
3.2 Configuration
Three DIP switches internal to the interface converter set the configuration
of the interface.
NOTE
Selectable functions are read only at power-on and should only be set
prior to applying power to the interface. The following figures illustrate
the factory-default conditions, which are:
Serial Port: IEEE:
9600 Baud Mode = IEEE 488 Controller
8 Data Bits Address = 10
2 Stop Bits Bus Terminator = LF; EOI Disabled
No Parity Talk-Back on Terminator Enabled
Serial Terminator = LF Talk-Back on Timeout Enabled
Echo Disabled
RTS/CTS Handshake
3. Getting Started
15
Figure 3-1. Factory-Default Settings.
1 2 3 4 5
6
7 8
OPEN
SW3
IEEE Addr
IEEE Term
EOI
10
LF
Disabled
Switch
Side
View
DOT
1 2 3 4 5 6 7 8
OPEN
SW2
Mode
Talk-Back on Timeout
Serial Term
C
Enabled
LF
Switch
Side
View
DOT
Echo
Parity
No Echo
No Parity
1 2 3 4 5 6 7 8
OPEN
SW1
Baud Rate
Handshake
Word Length
9600
RTS/CTS
8 Data Bits
Switch
Side
View
DOT
Talk-Back on Term
Enabled
Stop Bits
2 Stop Bits
CHAPTER 3: Getting Started
16
RS-232↔IEEE 488 INTERFACE CONVERTER
Note that the interface converter comes configured as an IEEE controller. In
this mode, the interface converter is designed to allow an RS-232 computer to
communicate with an IEEE peripheral such as a plotter. This controller mode
is described in detail in Chapter 4.
The interface converter may also be configured as an IEEE peripheral. As an
IEEE peripheral, it allows an IEEE controller to communicate with an RS-232
device. The peripheral mode of operation is described in detail in Chapter 5.
To modify any of these defaults, follow this simple procedure:
1. Disconnect the power supply from the AC line and from the interface. Also
disconnect any IEEE or serial cables.
WARNING
Never open the interface converter’s case while it is connected to the AC
line. Failure to observe this warning may result in equipment failure,
personal injury, or death.
2. Place the interface converter upside down on a flat surface. Remove the
four screws located near the rubber feet.
3. Return the interface converter to the upright position and carefully remove
the top cover.
4. Change whichever DIP-switch settings you need to change.
5. When you have made all your changes, reverse this procedure to
reassemble the interface converter.
3.3 Serial Port Settings
The first parameters to configure are those that correspond to the RS-232
port. These include baud rate, word length, number of stop bits, parity
selection and type of RS-232 handshake. Each of these are described in
the following sections.
3.3.1 S
ERIALBAUDRATE
The “baud rate” is the number of serial data bits per second transferred into
and out of the RS-232 interface. SW1-1 through SW1-4 determine the serial
baud rate. The factory-default baud rate is 9600 baud. Baud rates may be
selected from 110 to 57,600 baud. Refer to the following diagram for specific
baud rates.
17
CHAPTER 3: Getting Started
Figure 3-2. Switch SW1: Selecting the Serial Baud Rate.
Switch
Side
View
DOT
110
1 2 3 4 5
6
7 8
OPEN
1 2 3 4 5
6
7 8
OPEN
1800
300
1 2 3 4 5
6
7 8
OPEN
110
1 2 3 4 5
6
7 8
OPEN
1 2 3 4 5
6
7 8
OPEN
2400
110
1 2 3 4 5
6
7 8
OPEN
1 2 3 4 5
6
7 8
OPEN
3600
1 2 3 4 5
6
7 8
OPEN
4800135
1 2 3 4 5
6
7 8
OPEN
1 2 3 4 5
6
7 8
OPEN
720015 0
1 2 3 4 5
6
7 8
OPEN
1 2 3 4 5
6
7 8
OPEN
9600
600
1 2 3 4 5
6
7 8
OPEN
1 2 3 4 5
6
7 8
OPEN
19,200
1200
1 2 3 4 5
6
7 8
OPEN
1 2 3 4 5
6
7 8
OPEN
57,600
18
RS-232↔IEEE 488 INTERFACE CONVERTER
3.3.2 S
ERIALWORDLENGTH(DATABITS
)
SW1-6 determines the number of data bits, often referred to as word length,
for each serial character transmitted or received. The factory default is 8 data
bits.
Figure 3-3. Switch SW1: Selecting the Serial Word Length (Data Bits).
3.3.3 S
ERIALSTOPBITS
Switch SW1-8 determines the number of stop bits contained in each serial
character transmitted and received. The factory default is 2 stop bits.
Figure 3-4. Switch SW1: Selecting the Serial Stop Bits.
Switch
Side
View
DOT
1 2 3 4 5
6
7 8
OPEN
2 Stop Bits
1 2 3 4 5
6
7 8
OPEN
1 Stop Bit
1 2 3 4 5
6
7 8
OPEN
8 Data Bits
1 2 3 4 5
6
7 8
OPEN
7 Data Bits
Switch
Side
View
DOT
19
3.3.4 S
ERIALPARITY
Serial Parity is selected with S2-6 through S2-8. The interface converter
generates the selected parity during serial transmissions but it does not
check parity on data that is received. The factory default is parity disabled.
Figure 3-5. Switch SW2: Selecting the Serial Parity.
3.3.5 S
ERIALECHO
Serial data sent to the interface converter will be echoed back to the serial
host if SW2-5 is set to the open position. The factory default is Echo Disabled.
Figure 3-6. Switch SW2: Enabling or Disabling Echo.
1 2 3 4 5
6
7 8
OPEN
Echo Disabled
1 2 3 4 5
6
7 8
OPEN
Echo Enabled
Switch
Side
View
DOT
Switch
Side
View
DOT
1 2 3 4 5
6
7 8
OPEN
Mark Parity
1 2 3 4 5
6
7 8
OPEN
Odd Parity
1 2 3 4 5
6
7 8
OPEN
Space Parity
1 2 3 4 5
6
7 8
OPEN
Even Parity
1 2 3 4 5
6
7 8
OPEN
Parity Disabled
CHAPTER 3: Getting Started
20
RS-232↔IEEE 488 INTERFACE CONVERTER
3.3.6 S
ERIALHANDSHAKE
Switch SW1-5 is used to select hardware [RTS/CTS] or software [Xon/Xoff]
serial handshake control.
With X-ON/X-OFF, the interface converter issues an X-OFF character [ASCII
value of $13] when its buffer memory is near full. When the X-OFF character
is sent, there are still more than 1000 character locations remaining to protect
against buffer overrun. When it is able to accept more information, the interface converter issues an Xon character [ASCII value of $11]. The interface
converter also accepts X-ON/X-OFF on transmit from the serial host it is
communicating with. RTS/CTS serial control becomes inactive when XON/X-OFF is enabled. The RTS output is, however, set to an active high
state. The CTS input is not used for this handshake and may be left
floating (unconnected).
With RTS/CTS, the interface converter un-asserts RTS (sets RTS low) when
its buffer memory is near full. When RTS is un-asserted, there are still more
than 1000 character locations remaining to protect against buffer overrun.
When it is able to accept more information, the interface converter asserts
RTS (sets RTS high). The interface converter will not transmit data to the
serial host if it detects the CTS input un-asserted (low) when configured
for this hardware handshake.
The factory-default serial control is hardware, RTS/CTS.
Figure 3-7. Switch SW1: Selecting the Serial Handshake.
Switch
Side
View
DOT
1 2 3 4 5
6
7 8
OPEN
RTS/CTS
1 2 3 4 5
6
7 8
OPEN
X-ON/X-OFF
21
CHAPTER 3: Getting Started
3.4 Selecting Terminator Substitution
The interface converter can be configured to provide RS-232-to-IEEE-488 and
IEEE-488-to-RS-232 terminator substitution. This is useful when interfacing an
RS-232 device which only issues carriage return [CR] as an output terminator
to an IEEE controller which expects a carriage return followed by a line feed
[CR-LF].
In a case like that, the serial terminator should be selected for CR Only while
the IEEE terminator is set to CR-LF. When a serial CR character is received,
it is discarded, and an IEEE CR-LF is substituted for it. In the IEEE-to-RS-232
direction, the IEEE CR is unconditionally discarded. Upon receipt of the
IEEE LF, a serial CR is substituted.
The interface converter can be made totally data transparent by setting both
the serial and IEEE terminators to be CR Only or LF Only.
3.4.1 S
ERIALTERMINATOR
SW2-3 and SW2-4 select the serial terminators for the serial input and output.
The factory default is LF Only.
Figure 3-8. Switch SW2: Selecting the Serial Terminator.
Switch
Side
View
DOT
CR Only
1 2 3 4 5
6
7 8
OPEN
LF-CR
1 2 3 4 5
6
7 8
OPEN
1 2 3 4 5
6
7 8
OPEN
LF Only
1 2 3 4 5
6
7 8
OPEN
CR-LF
22
RS-232↔IEEE 488 INTERFACE CONVERTER
3.4.2 IEEE BUST
ERMINATOR
SW3-6 through SW3-8 set the IEEE bus terminators used for data sent or
received by the interface converter. EOI, a line used to signal the end of
a multiple character bus transfer, may also be enabled. If enabled, EOI
is asserted when the last selected bus terminator is sent. Factory default
is LF Only with EOI disabled.
Figure 3-9. Switch SW3: Selecting the IEEE Bus Terminator.
3.5 Selecting the Mode
SW2-1 sets the major operating mode of the interface converter. The IEEE
Controller (RS-232-to-IEEE converter) mode allows a serial host device to
send data to a single IEEE bus peripheral. Applications include interfacing
a listen-only or addressable IEEE printer/plotter to a serial printer port.
Refer to Chapter 4 for more detailed information on the controller mode
of operation.
The Peripheral mode is used when interfacing a serial device to an IEEE
controller. Data which is sent by the IEEE controller to the interface
converter is transmitted out its serial port. Data received from the serial
device is buffered by the interface converter until read by the IEEE controller.
Refer to Chapter 5 for more detailed information on the peripheral mode
of operation.
The factory default is the IEEE Controller mode, an RS-232-to-IEEE
converter.
Switch
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DOT
1 2 3 4 567 8
OPEN
LF Only
1 2 3 4 567 8
OPEN
CR-LF
1 2 3 4 567 8
OPEN
CR Only
1 2 3 4 567 8
OPEN
LF-CR
1 2 3 4 567 8
OPEN
EOI Disabled
1 2 3 4 567 8
OPEN
EOI Enabled
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