Measurement Micro 488EX User Manual
the smart approach to instrumentation
™
IOtech, Inc.
25971 Cannon Road Cleveland, OH 44146
Phone: (440) 439-4091 Fax: (440) 439-4093
E-mail: sales@iotech.com Internet: http://www.iotech.com
Micro 488/EX User’s Manual
Stand Alone Bus Controller
p/n Micro488/EX-901, Rev 2.1
©1992 by IOtech, Inc. Part No.Micro488/EX-901
Printed in the United States of America
Warranty Information
Your IOtech warranty is as stated on the product warranty card. You may contact IOtech by phone,
fax machine, or e-mail in regard to warranty-related issues.
Phone: (440) 439-4091, fax: (440) 439-4093, e-mail: sales@iotech.com
Limitation of Liability
IOtech, Inc. cannot be held liable for any damages resulting from the use or misuse of this product.
Copyright, Trademark, and Licensing Notice
All IOtech documentation, software, and hardware are copyright with all rights
reserved. No part of this product may be copied, reproduced or transmitted by
any mechanical, photographic, electronic, or other method without IOtech’s prior
written consent. IOtech product names are trademarked; other product names, as
applicable, are trademarks of their respective holders. All suppli ed IOtech
software (including miscellaneous support files, drivers, and sample programs)
may only be used on one installation. You may make archival backup copies.
FCC Statement
IOtech devices emit radio frequency energy in levels compliant with Federal Communications Commission rules
(Part 15) for Class A devices. If necessary, refer to the FCC booklet How To Identify and Resolve Radio-TV
Interference Problems (stock # 004-000-00345-4) which is available from the U.S. Government Printing Office,
Washington, D.C. 20402.
CE Notice
Many IOtech products carry the CE marker indicating they comply with the safety and emissions standards of the
European Community. As applicable, we ship these products with a Declaration of Conformity stating which
specifications and operating conditions apply.
Warnings, Cautions, Notes, and Tips
Refer all service to qualified personnel. This caution symbol warns of possible personal injury or equipment damage
under noted conditions. Follow all safety standards of professional practice and the recommendations in this
manual. Using this equipment in ways other than described in t his manual can present serious safety hazards or
cause equipment damage.
This ESD caution symbol urges proper handling of equipment or components sensitive to damage from electrostatic
discharge. Proper handling guidelines include the use of grounded anti-static mats and wrist straps, ESD-protective
bags and cartons, and related procedures.
Specifications and Calibration
Specifications are subject to change without notice. Significant changes will be addressed
in an addendum or revision to the manual. As applicable, IOtech calibrates its hardware to
published specifications. Periodic hardware calibration is not covered under the warranty
and must be performed by qualified personnel as specified in this manual. Improper
calibration procedures may void the warranty.
Quality Notice
IOtech has maintained ISO 9001 certification since 1996. Prior to shipment, we thoroughly test our products and
review our documentation to assure the highest quality in all aspects. In a spirit of continuous improvement, IOtech
welcomes your suggestions.
Table of Contents
Section 1 Introduction Page
1.1 Description 1.1
1.2 Available Accessories 1.2
1.3 Specifications 1.3
1.4 Abbreviations 1.4
Section 2 Getting Started Page
2.1 Inspection 2.1
2.2 Configuration 2.1
2.3 Serial Port Settings 2.3
2.3.1 Serial Baud Rate Selection 2.4
2.3.2 Serial Word Length Selection - Data Bits 2.5
2.3.3 Serial Stop Bit Selection 2.5
2.3.4 Serial Parity Selection 2.5
2.3.5 Serial Echo Selection 2.6
2.3.6 Serial Handshake Selection 2.7
2.4 Terminator Selection 2.8
2.4.1 Serial Terminator Selection 2.8
2.4.2 IEEE Bus Terminator Selection 2.9
2.5 Mode Selection 2.10
2.6 IEEE Address Selection 2.11
2.7 Feature Selections 2.12
2.7.1 Controller Pass-Thru Features 2.12
2.7.2 Peripheral Pass-Thru Features 2.13
2.8 Serial Interface 2.13
2.8.1 RS-232/RS-422 Signal Level Selection 2.13
2.8.2 Serial Signal Descriptions 2.14
2.8.3 Serial Cable Wiring Diagrams 2.16
2.9 General Operation 2.18
2.10 Is There Anyone Out There 2.20
Section 3 IEEE Operating Modes Page
3.1 Introduction 3.1
3.2 Operating Mode Transitions 3.1
3.3 System Controller 3.3
3.4 System Controller, Not Active Controller 3.4
3.5 Not System Controller 3.7
Table of Contents
Section 3 IEEE Operating Modes (con't) Page
3.6 Active Controller, Not System Controller 3.7
3.7 Controller Pass-Thru 3.8
3.8 Peripheral Pass-Thru 3.8
Section 4 General Programming Page
4.1 Introduction 4.1
4.2 Memory Usage 4.1
4.2.1 Serial I/O Buffers 4.1
4.2.2 Log Buffer 4.2
4.2.3 Macro Buffers 4.2
4.2.4 Changing Operational Modes 4.3
4.3 Clock and Timer Functions 4.3
4.3.1 Time 4.3
4.3.2 Date 4.5
4.3.3 Day of Week 4.6
4.3.4 Combinations 4.6
4.4 MACRO Programming 4.7
4.4.1 Creating a MACRO 4.7
4.4.2 Executing a MACRO 4.8
4.4.3 Debugging a MACRO 4.11
4.4.4 Logging MACRO Data 4.12
4.4.5 Event Driven MACRO Execution 4.13
4.4.6 Defining a STARTUP MACRO 4.16
4.4.7 Deleting a MACRO 4.18
4.4.8 Saving the LOG Buffer to Disk 4.18
4.4.9 Saving the MACRO Buffers to Disk 4.21
4.4.10 Restoring the MACRO Buffers From Disk 4.25
4.5 Restoring Lost Memory 4.27
Section 5 Command Descriptions Page
5.1 Introduction 5.1
5.2 Command Description Format 5.2
5.2.1 Syntax 5.2
5.2.1.1 Bus Addressing 5.3
5.2.1.2 Character Count 5.4
5.2.1.3 ASCII Characters 5.4
Table of Contents
Section 5 Command Descriptions (con't) Page
5.2.1.4 ASCII Character Strings 5.5
5.2.1.5 Terminators 5.5
5.2.2 Response 5.6
5.2.3 Mode 5.6
5.2.4 Bus States 5.7
5.2.5 Examples 5.8
5.3 The Commands 5.8
@5.9
@@ 5.10
ABORT 5.11
ARM 5.12
CASE 5.16
CLEAR 5.17
COMMENT 5.18
COUNT 5.19
DATE 5.20
DATE FORMAT 5.21
DAY 5.23
DAY FORMAT 5.24
DELAY 5.26
DISARM 5.27
DOMACRO 5.28
ENTER (Controller mode) 5.30
ENTER (Peripheral mode) 5.32
ERASE 5.34
ERASE LOG 5.35
ERROR 5.36
HELLO 5.37
ID 5.38
LOCAL 5.39
LOCAL LOCKOUT 5.40
LOG 5.41
LOG MEMORY 5.42
MACRO...ENDM 5.43
MASK 5.46
MEMORY 5.47
Table of Contents
Section 5 Command Descriptions (con't) Page
ON <event> DOMACRO 5.48
OUTPUT (Controller mode) 5.53
OUTPUT (Peripheral mode) 5.55
PASS CONTROL 5.57
PPOLL 5.58
PPOLL CONFIG 5.59
PPOLL DISABLE 5.61
PPOLL UNCONFIG 5.62
READ 5.63
READ LOG 5.64
REMOTE 5.65
REQUEST 5.66
RESET 5.67
RESUME 5.68
SAVE 5.69
SEND 5.70
SET DATE 5.73
SET DAY 5.75
SET TIME 5.76
SPOLL 5.77
STATUS 5.79
STERM 5.83
TERM 5.84
TIME 5.86
TIME FORMAT 5.87
TIME OUT 5.89
TRACE 5.90
TRIGGER 5.91
WAIT 5.92
Section 6 Controller Pass-Thru Operation Page
6.1 Introduction 6.1
6.2 Serial and IEEE Terminator Substitution 6.2
6.3 IEEE Address Selection 6.2
6.4 Talk Back On Terminator 6.3
6.5 Plotter Applications 6.4
6.6 Printer Applications 6.6
Table of Contents
Section 7 Peripheral Pass-Thru Operation Page
7.1 Introduction 7.1
7.2 Serial and IEEE Input Buffers 7.1
7.3 IEEE Data Transfers 7.2
7.3.1 Blind Bus Data Transfers 7.2
7.3.2 Controlled Bus Data Transfers 7.3
7.4 Serial Poll Status Byte Register 7.4
7.5 Use of Serial and Bus Terminators 7.6
7.6 IEEE 488 Bus Implementation 7.7
7.6.1 My Talk Address (MTA) 7.7
7.6.2 My Listen Address (MLA) 7.7
7.6.3 Device Clear (DCL and SDC) 7.8
7.6.4 Interface Clear (IFC) 7.8
7.6.5 Serial Poll Enable (SPE) 7.8
7.6.6 Serial Poll Disable (SPD) 7.8
7.6.7 Unlisten (UNL) 7.8
7.6.8 Untalk (UNT) 7.8
7.7 IEEE Address Selection 7.9
7.7.1 Listen Only Mode 7.9
7.8 IEEE to Serial Applications 7.10
Section 8 IEEE 488 Primer Page
8.1 History 8.1
8.2 General Structure 8.1
8.3 Send It To My Address 8.4
8.4 Bus Management Lines 8.4
8.4.1 Attention (ATN) 8.4
8.4.2 Interface Clear (IFC) 8.5
8.4.3 Remote Enable (REN) 8.5
8.4.4 End Or Identify (EOI) 8.5
8.4.5 Service Request (SRQ) 8.5
8.5 Handshake Lines 8.6
8.5.1 Data Valid (DAV) 8.6
8.5.2 Not Ready For Data (NRFD) 8.6
8.5.3 Not Data Accepted (NDAC) 8.6
8.6 Data Lines 8.7
8.7 Multiline Commands 8.7
Table of Contents
Section 8 IEEE 488 Primer (con't) Page
8.7.1 Go To Local (GTL) 8.7
8.7.2 Listen Address Group (LAG) 8.8
8.7.3 Unlisten (UNL) 8.8
8.7.4 Talk Address Group (TAG) 8.8
8.7.5 Untalk (UNT) 8.8
8.7.6 Local Lockout (LLO) 8.8
8.7.7 Device Clear (DCL) 8.8
8.7.8 Selected Device Clear (SDC) 8.9
8.7.9 Serial Poll Disable (SPD) 8.9
8.7.10 Serial Poll Enable (SPE) 8.9
8.7.11 Group Execute Trigger (GET ) 8.9
8.7.12 Take Control (TCT) 8.9
8.7.13 Secondary Command Group (SCG) 8.9
8.7.14 Parallel Poll Configure (PPC) 8.10
8.7.15 Parallel Poll Unconfigure (PPU) 8.10
8.8 More On Service Requests 8.10
8.8.1 Serial Poll 8.11
8.8.2 Parallel Poll 8.11
Section 9 Service Information Page
9.1 Factory Service 9.1
9.2 Theory of Operation 9.1
9.3 Micro488/EX Mother Board Comp. Layout 9.3
9.4 Micro488/EX Serial I/O
Board Comp. Layout 9.4
9.5 Replaceable Parts List 9.5
Appendix A Micro488/EX Command Summary A.1
Appendix B Micro488/EX Error Codes & Messages B.1
Appendix C IEEE Command and Address Messages C.1
Appendix D Sample Terminal Programs D.1
Section 1 Introduction
Introduction
1.1 Description
The Micro488/EX Stand Alone Bus Controller converts a host RS-232 or RS-422
computer into an IEEE 488 bus talker, listener and controller. The Micro488/EX
provides full IEEE 488-1978 bus implementation including advance capabilities such
as PASS CONTROL, RECEIVE CONTROL, PARALLEL POLL, SERIAL POLL and
SECONDARY ADDRESSING. The device may be located several hundred feet from
the host and may control as many as fourteen 488 bus instruments. In the noncontroller mode the Micro488/EX converts the host into a bus peripheral for data
processing and mass storage. The Micro488/EX interprets simple high level commands
sent from the computer's serial port and performs the necessary, and usually complex,
bus control and handshaking. The commands and protocol are similar to those used by
the Hewlett Packard HP-85 computer.
A unique feature of the Micro488/EX is its macro capability. Macros are miniprogram sequences that can be used to collect data for later recall by the serial host
computer. Up to 100 different macros can be defined and maintained in non-volatile
memory. The data collected by macros can be immediately sent to the serial host or
placed into a non-volatile log buffer for later recall. The data collected can also be date
and time stamped using the Micro488/EX's internal time-day-date clock. Macros can
also be executed as a result of some external event, such as SRQs or Errors.
Additional features provide a transparent IEEE to serial converter and a serial to
IEEE pass-thru controller.
As a serial to IEEE 488 converter, the Micro488/EX 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 Micro488/EX is a peripheral to an IEEE
488 controller. Data received from the controller is sent to the serial device and data
received from the serial device is buffered for transmission to the IEEE 488 controller.
The Micro488/EX can inform the host, by the serial poll status byte, that it has received
data from the serial device.
1.1
Section 1 Introduction
1.2 Available Accessories
Additional accessories that can be ordered for the Micro488/EX include:
CA-7-1 1.5 foot IEEE 488 Cable
CA-7-2 6 foot IEEE 488 Cable
CA-7-3 6 foot shielded IEEE 488 Cable
CA-7-4 6 foot reverse entry IEEE 488 Cable
CA-11 IBM PC/XT/PS2 to Micro488/EX RS-232 Cable
CA-12 Macintosh 512 to Micro488/EX RS-232 Cable
CA-22 Macintosh II/SE/Plus to Micro488/EX RS-232 Cable
CA-23 IBM AT to Micro488/EX RS-232 Cable
CN-20 Right Angle IEEE 488 adapter, male and female
CN-22 IEEE 488 Multi-tap bus strip, four female connectors in parallel
CN-23 IEEE 488 panel mount feed-through connector, male and female
ABC488 IEEE 488 ABC switch
Rack488-3 5-1/4" by 19" rack mount for one Micro488/EX
Rack488-4 5-1/4" by 19" rack mount for two Micro488/EX's
127-0920 Additional instruction manual
1.2
Section 1 Introduction
&$87,21
Please read this manual carefully! If equipment is used in any
manner not specified in this m anual, the protection provided by
the equipment may be impaired.
1.3 Specifications
IEEE 488
&$87,21
The IEEE 488 terminal must only be used to control a nonisolated IEEE 4 88 system. The common mode voltage (cable
shell to earth) must be zero.
Terminal Installation Category:
O
Standard
: Not Applicable. O
: Category 1.
CE
Implementation:
O C1, C2, C3, C4 and C28 controller subsets. SH1, AH1, T6, TE0, L4, LE0,
SR1, RL0, PP0, DC1, DT1, E1
Terminators:
O Selectable CR, LF, LF-CR, and CR-LF with EOI.
Connector:
O Standard IEEE 488 connector with metric studs.
Serial Interface
&$87,21
The RS-232/RS-422 terminal is only for connecting devices
having signals at serial communication levels.
Terminal Installation Category:
O
Standard
: Not Applicable. O
: Category 1.
CE
EIA RS-232C:
O AB, BA, BB, CA, CB.
1.3a
Section 1 Introduction
EIA RS-422A:
O
Balanced volta ge on TxD and RxD.
Character Set:
O
Asynchronous bit serial.
Output Voltage:
O
±5 volts minimum (RS-232C); 3.5 volts typical (RS-422A).
Input Voltage:
O
±3 volts minimum; ±15 volts maximum.
Baud Rate:
O
Selectable 110,300,600,1200,1800,2400,3600,4800,7200,9600, and 19200.
Data Format:
O
Selectable 7 or 8 data bits; 1 or 2 stop bits; odd, even, mark, space and no
parity on transmit.
Duplex:
O
Full with Ec ho/No Echo.
Serial Control:
O
Selectable CTS/RTS or XON/XOFF.
Terminators:
O
Selectable CR, LF, LF-CR and CR-LF.
Connector:
O
25-pin Sub-D male. RS-232C DCE configured.
Clock
Accuracy:
O
1 minute per month typical.
Battery Life:
O
10 years typical.
Information Provided:
O
Provides hours, minutes, second s, day, month, date and year.
General
Terminal Installation Category:
O
Standard
: Not Applicable.
O
:
CE
Category 1 for all terminals.
Dimensions:
O
188 mm deep x 140 mm wide x 68 mm high (7.39” x 5.5” x 2.68”).
1.3b
Section 1 Introduction
Weight:
O 1.55 kg (3.6 lbs.).
Operating Environment:
O
Standard
to 70% RH to 35
3% RH/
o
: Indoor use, 0 to 50
o
o
C from 35 to 5 0oC. RH up to 31oC decreasing linearly
C. Linearly derate 2000 m, 0 to 40oC; 80% maximum
C; 0 O
:
CE
Indoor use at altitudes below
o
4% RH/
C to 40oC.
Data Buffer:
O Approximately 29000 characters total, dynamically allocated and non-volatile.
Data maintained for up to 10 years typical.
Controls:
O Power Switch (external), IEEE and Serial parameter switches (internal).
Jumper selection of RS-23 2 or RS-422 operation ( internal)
Indicators:
O LED indicators for TALK, LISTEN, SRQ, ERROR and POWER.
Power:
O An external power supply is provided with the Micro488/EX: Input is 105 to
125 VAC or 210 to 250 VAC; 50-60 Hz, 10 VA maximum. External power
supply 9 VDC output is to be connected to the Micro488/EX power input marked
10 VDC MAX @ 600 mA.
&$87,21
Do not connect AC power line directly to the Micro488/EX.
Otherwise, equipment may be damaged.
:$51,1*
Do not use this interface outdoors! The interface is intended for
indoor use only! Outdoor conditions could result in equipment
failure, bodily injury or death!
1.3c
Section 1 Introduction
1.4 Abbreviations
The following IEEE 488 abbreviations 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
REN Remote Enable
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
1.4
Section 2 Getting Started
Getting Started
2.1 Inspection
The Micro488/EX was carefully inspected, both mechanically and electrically,
prior to shipment. When you receive the interface, carefully unpack all items from the
shipping carton and check for any obvious signs of physical damage which may have
occurred during shipment. Immediately report any such damage found to the shipping
agent. Remember to retain all shipping materials in the event that shipment back to the
factory becomes necessary.
Every Micro488/EX is shipped with the following....
Micro488/EX IEEE 488 Bus Controller
•
127-0920 Instruction Manual
•
Power Supply TR-2; 115V or
•
TR-2E; 220/230V
2.2 Configuration
Three DIP switches internal to the Micro488/EX 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 = System Controller
8 Data Bits Address = 10
2 Stop Bits Bus Terminator = CR-LF; EOI Disabled
No Parity Talk-back E nabled
Serial Terminator = CR-LF
Echo Disabled
RTS/CTS Handshake
2.1
Section 2 Getting Started
SW3 Factory Default Settings
IEEE Addr
IEEE Term
EOI
SW2 Factory Default Settings
Mode
Serial Term
Echo
Parity
12345678
SW3
OPEN
10
CR-LF
Disabled
12345678
SW2
SC
CR-LF
No Echo
No Parity
OPEN
Switch
Side
View
Switch
Side
View
DOT
DOT
SW1 Factory Default Settings
Baud Rate
Handshake
Word Length
Pass Thru Feature
Stop Bits
12345678
SW1
9600
RTS/CTS
8 Data Bits
Enabled
2 Stop Bits
OPEN
Switch
Side
View
DOT
2.2
Section 2 Getting Started
Note that the Micro488/EX comes configured as an IEEE controller. In this mode
the Micro488/EX is designed to allow a serial host computer to control up to 14 IEEE
488 devices. This mode of operation is described in detail, along with its command
descriptions, in Sections 3, 4 and 5. Theses sections also cover the peripheral mode of
operation.
The Micro488/EX can be configured to transparently communicate with a single
IEEE peripheral, such as a plotter. This Controller Pass-Thru mode is described in
detail in Section 6.
The Micro488/EX may also be configured as a transparent IEEE Pass-Thru
Peripheral. As a Pass-Thru Peripheral, the Micro488/EX allows an IEEE controller to
communicate with a serial device. The Peripheral Pass-Thru mode of operation is
described in detail in Section 7.
To modify any of these defaults, follow this simple procedure: Disconnect the
power supply from the AC line and from the interface. Disconnect any IEEE or serial
cables prior to disassembly.
WARNING
Never open the Micro488/EX case while it is
connected to the AC line. Failure to observe this
warning may result in equipment failure, personal
injury or death.
Remove the four screws located in each corner of the rear panel. Hold the case
firmly and pull the rear panel outward, noting the slot location of the main circuit
board. Modify those parameters which are appropriate for your installation and
reassemble the unit. Slide the main circuit board into the previously noted slot and
finish reassembly by tightening the four screws into the rear panel.
2.3 Serial Port Settings
The first parameters to configure are those that correspond to the RS-232/RS-422
port. These include baud rate, word length, number of stop bits, parity selection and
type of serial handshake. Each of these are described in the following sections.
2.3
Section 2 Getting Started
2.3.1 Serial Baud Rate Selection
Baud rate defines the number of serial bits per second transferred into
and out of the serial 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 19200 baud. Refer to the following diagram for
specific baud rates.
SW1 View for Serial Baud Rate Selection
12345678
110 1800
OPEN
12345678
110 2400
OPEN
12345678
110 3600
OPEN
12345678
135 4800
OPEN
12345678
150 7200
OPEN
12345678
12345678
OPEN
12345678
OPEN
12345678
OPEN
12345678
OPEN
12345678
OPEN
12345678
Switch
Side
View
DOT
300 9600
OPEN
12345678
600 19200
OPEN
12345678
1200 19200
OPEN
OPEN
12345678
OPEN
12345678
OPEN
2.4
Section 2 Getting Started
2.3.2 Serial Word Length Selection - Data Bits
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.
SW1 View of Serial Word Length (Data Bits) Selection
12345678
OPEN
12345678
OPEN
Switch
Side
View
DOT
8 Data Bits 7 Data Bits
2.3.3 Serial Stop Bit Selection
Switch SW1-8 determines the number of stop bits contained in each
serial character transmitted and received. The factory default is 2 stop bits.
SW1 View for Serial Stop Bit Selection
12345678
OPEN
12345678
1 Stop Bit 2 Stop Bits
Switch
Side
View
OPEN
DOT
2.3.4 Serial Parity Selection
Serial Parity is selected with S2-6 through S2-8. The Micro488/EX
generates the selected parity during serial transmissions but it does not
check parity on data that is received. The factory default is parity disabled.
2.5
Section 2 Getting Started
12345678
12345678
SW2 View for Serial Parity Selection
12345678
OPEN
Odd Parity Mark Parity
12345678
OPEN
Even Parity Space Parity
12345678
OPEN
Parity Disabled
OPEN
OPEN
Switch
DOT
Side
View
2.3.5 Serial Echo Selection
Serial data sent to the Micro488/EX will be echoed back to the serial
host if SW2-5 is set to the open position. Factory default is Echo Disabled.
12345678
OPEN
Echo Disabled Echo Enabled
SW2 View for Echo Selection
12345678
OPEN
Switch
DOT
Side
View
2.6
Section 2 Getting Started
2.3.6 Serial Handshake Selection
Switch SW1-5 is used to select between hardware [
software [
With
value of
&H13
XON/XOFF
XON/XOFF
] when its buffer memory is near full. When issued, there are
] serial handshake control.
, the Micro488/EX issues an
XOFF
RTS/CTS
character [ASCII
] or
greater than 1000 character locations remaining to protect against buffer
overrun. When it is able to accept more information it issues an
character [ASCII value of
issues an
accepts
with.
XON/XOFF
RTS/CTS
enabled. The
character at reset or power-on. The Micro488/EX also
XON
on transmit from the serial host it is communicating
serial control becomes inactive when
output is, however, set to an active high state. The
RTS
&H11
]. With this handshake, the Micro488/EX
XON/XOFF
XON
is
CTS
input is not used for this handshake and may be left floating (unconnected).
With
RTS/CTS
, the Micro488/EX un-asserts
(low) when its
RTS
buffer memory is near full. When un-asserted, there are greater than 1000
character locations remaining to protect against buffer overrun. When it is
able to accept more information it asserts (high)
will not transmit data to the serial host if it detects the
. The Micro488/EX
RTS
input un-
CTS
asserted (low) when configured for this hardware handshake.
The factory default serial control is hardware,
SW1 View for Serial Handshake Selection
12345678
OPEN
RTS/CTS Xon/Xoff
12345678
OPEN
RTS/CTS
Switch
Side
View
.
DOT
2.7
Section 2 Getting Started
2.4 Terminator Selection
In the Controller and Peripheral Modes, the Micro488/EX is not sensitive as to
whether CR or LF is used as a serial input terminator to a command. In general, it
requires only one of either to cause command execution. The IEEE input terminator is
fixed to LF. The switches that allow terminator selection, shown in the following
diagrams, set only the serial output and IEEE output terminators for these modes of
operation.
In the transparent Pass-Thru modes, the Micro488/EX 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 terminato r to an IEEE control ler which expects a carriage return followed b y a
line feed [CR-LF].
In the above case, the serial terminator should be selected for CR Only while the
IEEE terminator is set to CR-LF. When a serial CR ch aract er i s recei v ed , it i s d i s carde d
and substituted with an IEEE CR-LF. 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 Micro488/EX can be made totally data transparent in the Pass-Thru modes
by setting both the serial and IEEE terminators to be CR Only or LF Only.
2.4.1 Serial Terminator Selection
SW2-3 and SW2-4 select the serial terminators for the serial input
(Pass-Thru Modes Only) and output. The factory default is CR-LF.
2.8
Section 2 Getting Started
SW2 View for Serial Terminator Selection
12345678
OPEN
12345678
OPEN
Switch
Side
View
DOT
CR Only LF-CR
12345678
OPEN
12345678
OPEN
LF Only CR-LF
2.4.2 IEEE Bus Terminator Selection
SW3-6 through SW3-8 set the IEEE bus terminators used for data sent
or received (Pass-Thru modes only) by the Micro488/EX. 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 CR-LF with EOI disabled.
SW3 View for IEEE Bus Terminator Selection
12345678
OPEN
CR Only LF-CR
12345678
OPEN
LF Only CR-LF
12345678
OPEN
EOI Disabled EOI Enabled
12345678
OPEN
12345678
OPEN
12345678
OPEN
Switch
DOT
Side
View
2.9
Section 2 Getting Started
2.5 Mode Selection
SW2-1 and SW2-2 set the major operating mode of the Micro488/EX. There are
four distinct modes of operation.
1. System Controller
2. Peripheral
3. Controller Pass-Thru
4. Peripheral Pass-Thru
As a System Controller, the Micro488/EX accepts simple high-level ASCII
commands from a serial host. It interprets these commands and performs the required
bus action to bi-directionally communicate with up to 14 IEEE devices. As a
Peripheral, the Micro488/EX becomes a bus device. It accepts simple high-level
ASCII commands from a serial host and interprets these commands and status to
communicate with anot her IEEE controller. Applications incl ude computer controlled
automatic test systems. These modes of operation are discussed in Sections 3, 4 and 5.
The IEEE Controller Pass-Thru (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 Section 6 for more detailed information on the Controller Pass-Thru mode of
operation.
The Peripheral Pass-Thru mode is used when interfacing a serial device to an
IEEE controller. Data which is sent by the IEEE controller to the Micro488/EX is
transmitted out its serial port. Data received from the serial device is buffered by the
Micro488/EX until read by the IEEE controller. Refer to Section 7 for more detailed
information on the Peripheral Pass-Thru mode of operation.
The factory default is the System Controller mode.
2.10
Section 2 Getting Started
SW2 View for Mode Selection
12345678
OPEN
System Controller
12345678
OPEN
Controller Pass-Thru
12345678
OPEN
Peripheral
12345678
OPEN
Peripheral Pass-Thru
Switch
Side
View
DOT
2.6 IEEE Address Selection
SW3-1 through SW3-5 select the IEEE bus address of the Micro488/EX when in
the System Controller, Peripheral and Peripheral Pass-Thru modes. These same
switches are used in the Controller Pass-Thru mode to select the address of the device
that will be controlled. [Refer to Section 6 for additional information]. The address is
selected by simple binary weighting with SW3-1 being the least significant bit and
SW3-5 the most significant. The factory default is address 10.
2.11
Section 2 Getting Started
SW3 View for IEEE Address Selection
12345678
0
1
OPEN
0 x 16
1 x 8
0 x 4
1 x 2
0 x 1
+
Switch
Side
View
= 0
= 8
= 0
= 2
= 0
DOT
IEEE Address = 10
2.7 Feature Selections
The functions of the remaining switches are dependent on the mode selected. A
brief description of each of these features follows. You should refer to the listed
sections for additional information.
2.7.1 Controller Pass-Thru Features
In the IEEE Controller (RS-232 to IEEE 488 Converter) mode, SW1-7
is used to determine whether the interface should, after sending the IEEE
bus terminators, address the attached bus device to talk. The factory default
is Talk-back On Terminator enabled.
Refer to Section 6 for complete details on these features.
SW1 View for Controller Talk-Back on Terminator Selection
12345678
OPEN
Talk Back on
Terminator Disabled
12345678
OPEN
Talk Back on
Terminator Enabled
Switch
Side
View
DOT
2.12
Section 2 Getting Started
2.7.2 Peripheral Pass-Thru Features
In the Peripheral Pass-Thru (IEEE 488 to RS-232 converter) mode, SW1-7
enables the interface t o assert the SRQ IEEE bus interface lin e to indicate
that it has received the last switch selected serial terminator character from
the serial device. Refer to Section 7 for more information.
SW1 View for Peripheral SRQ on Last Serial Terminator
12345678
OPEN
SRQ on Last
Terminator Disabled
12345678
OPEN
SRQ on Last
Terminator Enabled
Switch
Side
View
DOT
2.8 Serial Interface
The Micro488/EX has the ability to output signal levels that are compatible with
either RS-232 or RS-422. An internal DIP shorting plug determines which electrical
specification is chosen. If the interface is to be connected to an IBM PC/XT/AT/PS2 or
compatible, the RS-232 level should be selected. If it will be connected to a Macintosh
512K/Plus/SE/II, the RS-422 level should be used. For connection to other computers,
refer to the manufacturer's manual to determine which levels are supported.
2.8.1 RS-232/RS-422 Signal Level Selection
The Micro488/EX's factory default signal levels are compatible with
RS-232. To select RS-422 levels, carefully remove the 8 position shorting
plug with a small flat blade screwdriver from J106. Install the DIP jumper
into J205 making certain that all of the pins on the shorting plug are
inserted correctly.
2.13
Section 2 Getting Started
Selecting RS-232 or RS-422 Signal Levels
Shorting Plug
J205
RS-422 RS-232
J206
2.8.2 Serial Signal Descriptions
The Micro488/EX is equipped with a standard DB-25S connector on
its rear panel and requires a standard DB-25P mating connector. The
Micro488/EX's connector is configured as DCE type equipment for RS-232
communications, which means the Micro488/EX always transmits data on
Pin 3 and receives data on Pin 2. The following lists and describes the RS232 and RS-422 signals provided on the Micro488/EX.
Rear View of the Micro488/EX's Serial Connector
CTS
+VTEST
GND
13
25
RTS
+VTEST
-RXD
-TXD
1
14
2.14
+TXD
+RXD
Section 2 Getting Started
-RxD
-TxD
CTS
Receive Data - Input - Pin 2
This pin accepts serial data sent by the RS-232 or RS-422 host. The
serial data is expected with the word length, baud rate, stop bits and
parity selected by the internal switches. The signal level is low true.
Transmit Data - Output - Pin 3
This pin transmits serial data to the RS-232 or RS-422 host. The
serial data is sent with the word length, baud rate, stop bits and parity
selected by the internal switches. The signal level is low true.
Clear To Send - Input - Pin 4
The
input is used as a hardware handshake line to prevent the
CTS
Micro488/EX from transmitting serial data when the RS-232 host is
not ready to accept it. When
RTS/CTS
internal switches, the Micro488/EX will not transmit data out
handshake is selected on the
-TxD
while this line is un-asserted (low). If the RS-232 host is not capable
of driving this line it can be connected to the
the Micro488/EX. If
XON/XOFF
handshake is selected, the
Vtest
output (Pin 6) of
line
CTS
is not tested to determine if it can transmit data.
RTS
Vtest
Gnd
Request To Send - Output - Pin 5
The
output is used as a hardware handshake line to prevent the
RTS
RS-232/RS-422 host from transmitting serial data if the Micro488/EX
is not ready to accept it. When
RTS/CTS
the internal switches, the Micro488/EX will drive the
handshake is selected on
output
RTS
high when there are greater than 1000 character locations available in
its internal buffer. If the number of available locations drops to less
than 1000, the Micro488/EX will un-assert (low) this output. If
XON/XOFF
handshake is selected, the
line will be permanently
RTS
driven active high.
Test Voltage - Output - Pin 6
This pin is connected to +5 volts through a 1KΩ resistor. It is also
common to
Vtest
on pin 9.
Ground - Pin 7
This pin sets the ground reference point for the other RS-232 inputs
and outputs.
2.15
Section 2 Getting Started
Vtest
+RxD
+TxD
Test Voltage - Output - Pin 9
This pin is connected to 5 volts through a 1KΩ resistor. It is also
common to
Vtest
on pin 6.
Receive Data Plus - Input - Pin 14
This pin accepts serial data sent by the RS-422 host. The serial data
is expected with the word length, baud rate, stop bits and parity
selected by the internal switches. The signal level is high true and
only connected to this pin when RS-422 operation is selected. It is
180° out of phase with
-RxD
.
Transmit Data Plus - Output - Pin 16
This pin transmits serial data to the RS-422 host. The serial data is
sent with the word length, baud rate, stop bits and parity selected by
the internal switches. The signal level is high true and only connected
to this pin when RS-422 operation is selected. It is 180° out of phase
with
-TxD
.
2.8.3 Serial Cable Wiring Diagrams
If a cable was not purchased with the interface, the following diagrams
will be helpful in making your own cable. Simple soldering skills and an
attention to detail will ensure successful construction.
Macintosh to Micro488/EX Wiring Diagram (RS-422)
Macintosh to Micro488/EX
DB-9 Male DB-25 Male
RTS
CTS
-TxD
Gnd
-RxD
+TxD
+RxD
6
7
5
3
9
4 14 +Rxd
8 16 +Txd
4
5
2
7
3
CTS
RTS
-RxD
Gnd
-Txd
2.16
Loading...