Tektronix M1700 Series of Digital I/O to Computer Interfaces Users Guide

M1700

Series of Digital I/O To Computer Interfaces
User Guide

A GREATER MEASURE OF CONFIDENCE

WARRANTY

Hardware

Keithley Instruments, Inc. warrants that, for a period of one (1) year from the date of shipment (3 years for Models 2000, 2001, 2002, 2010 and 2700), the
Keithley Hardware product will be free from defects in materials or workmanship. This warranty will be honored provided the defect has not been caused
by use of the Keithley Hardware not in accordance with the instructions for the product. This warranty shall be null and void upon: (1) any modification of
Keithley Hardware that is made by other than Keithley and not approved in writing by Keithley or (2) operation of the Keithley Hardware outside of the
environmental specifications therefore.

Upon receiving notification of a defect in the Keithley Hardware during the warranty period, Keithley will, at its option, either repair or replace such Keithley Hard­ware. During the first ninety days of the warranty period, Keithley will, at its option, supply the necessary on site labor to return the product to the condition prior to
the notification of a defect. Failure to notify Keithley of a defect during the warranty shall relieve Keithley of its obligations and liabilities under this warranty.

Other Hardware

The portion of the product that is not manufactured by Keithley (Other Hardware) shall not be covered by this warranty, and Keithley shall have no duty of
obligation to enforce any manufacturers' warranties on behalf of the customer. On those other manufacturers’ products that Keithley purchases for resale,
Keithley shall have no duty of obligation to enforce any manufacturers’ warranties on behalf of the customer.

Software

Keithley warrants that for a period of one (1) year from date of shipment, the Keithley produced portion of the software or firmware (Keithley Software) will
conform in all material respects with the published specifications provided such Keithley Software is used on the product for which it is intended and other­wise in accordance with the instructions therefore. Keithley does not warrant that operation of the Keithley Software will be uninterrupted or error-free and/
or that the Keithley Software will be adequate for the customer's intended application and/or use. This warranty shall be null and void upon any modification
of the Keithley Software that is made by other than Keithley and not approved in writing by Keithley.

If Keithley receives notification of a Keithley Software nonconformity that is covered by this warranty during the warranty period, Keithley will review the
conditions described in such notice. Such notice must state the published specification(s) to which the Keithley Software fails to conform and the manner
in which the Keithley Software fails to conform to such published specification(s) with sufficient specificity to permit Keithley to correct such nonconfor­mity. If Keithley determines that the Keithley Software does not conform with the published specifications, Keithley will, at its option, provide either the
programming services necessary to correct such nonconformity or develop a program change to bypass such nonconformity in the Keithley Software.
Failure to notify Keithley of a nonconformity during the warranty shall relieve Keithley of its obligations and liabilities under this warranty.

Other Software

OEM software that is not produced by Keithley (Other Software) shall not be covered by this warranty, and Keithley shall have no duty or obligation to
enforce any OEM's warranties on behalf of the customer.

Other Items

Keithley warrants the following items for 90 days from the date of shipment: probes, cables, rechargeable batteries, diskettes, and documentation.

Items not Covered under Warranty

This warranty does not apply to fuses, non-rechargeable batteries, damage from battery leakage, or problems arising from normal wear or failure to follow
instructions.

Limitation of Warranty

This warranty does not apply to defects resulting from product modification made by Purchaser without Keithley's express written consent, or by misuse
of any product or part.

Disclaimer of Warranties

EXCEPT FOR THE EXPRESS WARRANTIES ABOVE KEITHLEY DISCLAIMS ALL OTHER WARRANTIES, EXPRESS OR IMPLIED, INCLUD­ING WITHOUT LIMITATION, ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. KEI­THLEY DISCLAIMS ALL WARRANTIES WITH RESPECT TO THE OTHER HARDWARE AND OTHER SOFTWARE.

Limitation of Liability

KEITHLEY INSTRUMENTS SHALL IN NO EVENT, REGARDLESS OF CAUSE, ASSUME RESPONSIBILITY FOR OR BE LIABLE FOR: (1)
ECONOMICAL, INCIDENTAL, CONSEQUENTIAL, INDIRECT, SPECIAL, PUNITIVE OR EXEMPLARY DAMAGES, WHETHER CLAIMED
UNDER CONTRACT, TORT OR ANY OTHER LEGAL THEORY, (2) LOSS OF OR DAMAGE TO THE CUSTOMER'S DATA OR PROGRAM­MING, OR (3) PENALTIES OR PENALTY CLAUSES OF ANY DESCRIPTION OR INDEMNIFICATION OF THE CUSTOMER OR OTHERS FOR
COSTS, DAMAGES, OR EXPENSES RELATED TO THE GOODS OR SERVICES PROVIDED UNDER THIS WARRANTY.

Keithley Instruments, Inc. 28775 Aurora Road • Cleveland, Ohio 44139 • 440-248-0400 • Fax: [phone]

1-888-KEITHLEY (534-8453) • www.keithley.com

Sales Offices:BELGIUM: Bergensesteenweg 709 • B-1600 Sint-Pieters-Leeuw • 02-363 00 40 • Fax: [phone]

CHINA: Yuan Chen Xin Building, Room 705 • 12 Yumin Road, Dewai, Madian • Beijing 100029 • 8610-6202-2886 • Fax: [phone]
FINLAND: Tietäjäntie 2 • 02130 Espoo • Phone: [phone] • Fax: [phone]
FRANCE: 3, allée des Garays • 91127 Palaiseau Cédex • 01-64 53 20 20 • Fax: [phone]
GERMANY: Landsberger Strasse 65 • 82110 Germering • 089/84 93 07-40 • Fax: [phone]
GREAT BRITAIN: Unit 2 Commerce Park, Brunel Road • Theale • Berkshire RG7 4AB • 0118 929 7500 • Fax: [phone]
INDIA: Flat 2B, Willocrissa • 14, Rest House Crescent • Bangalore 560 001 • 91-80-509-1320/21 • Fax: [phone]
ITALY: Viale San Gimignano, 38 • 20146 Milano • 02-48 39 16 01 • Fax: [phone]
JAPAN: New Pier Takeshiba North Tower 13F • 11-1, Kaigan 1-chome • Minato-ku, Tokyo 105-0022 • 81-3-5733-7555 • Fax: [phone]
KOREA: 2FL., URI Building • 2-14 Yangjae-Dong • Seocho-Gu, Seoul 137-888 • 82-2-574-7778 • Fax: [phone]
NETHERLANDS: Postbus 559 • 4200 AN Gorinchem • 0183-635333 • Fax: [phone]
SWEDEN: c/o Regus Business Centre • Frosundaviks Allé 15, 4tr • 169 70 Solna • 08-509 04 679 • Fax: [phone]
SWITZERLAND: Kriesbachstrasse 4 • 8600 Dübendorf • 01-821 94 44 • Fax: [phone]
TAIWAN: 1FL., 85 Po Ai Street • Hsinchu, Taiwan, R.O.C. • 886-3-572-9077• Fax: [phone]

4/02

User Guide

for

the

M

1700

Digital

Series

I/O

To

Computer Interfaces

R

vision

Copyright Keithley MetraByte

Pan

A

Number:

-

June

Of

1991

24403

Corp.

1991

All

products manufactured

materials

the

warranty

This

original

period

warranty

and

worksmanship for

purchaser.

will,

does not apply

by

Any product

at

the

option

Warranty Information

Keithley MetraByte

a

period

of

that

is

of

Keithlq

to

products

damaged

are

one

year

found

to

MetraByte,

warranted

horn

be

by

improper

Warning

the

date

defective

be

repaired

against

of

delivery to

within

or

use.

defective

the

replaced.

gdthlep

use

of

level

of

Information

reliable.

for

of

or otherwise under

However,

the

use

third

parties that may result

Note:

MetraByte"

Basic"

Is

MetraEyte

this

product.

rcliabiiity

furnished

of

such information nor

is

a

a

trademark

p8sumes

This

suitabIe

by

the

KeiMey

any

patent

trademark of

of

Dartrnouth

no

liability

product

for

is

not designed with components

use

in

life

Disclaimer

Keithley MetraByte

MetraByte

from

rights

Keithley

Corporation assumes

for

any

its

use.

of

Keithley

MehaByte Corporation.

College.

for

support

is

believed

damages

consequent

or

critical

to

be

accurate

no

infringements of patents

No

license

is

granted

MetraByte

Corporation.

to

the

of

applications.

and

responsibility

or

other

by

implication

a

rights

IBMQ

is

a

registered

PC.

XT,

AT,

PS/2,

tional Business Machines

Microsoft@

Turbo

is

t3

is

a

bademark

and

a

registered trademark

registered trademark of Borland

oflnternational Business Machines Corporation.

Micro

Channel Architecture@

Corporation.

of

-

are trademarks

Microsoft Corporation.

International

iv

-

of

Intema-

New Contact Information

Keithley Instruments, Inc.

28775 Aurora Road

Cleveland, OH 44139

Technical Support: 1-888-KEITHLEY

Monday – Friday 8:00 a.m. to 5:00 p.m (EST)

Fax: [phone]

Visit our website at http://www.keithley.com

Safety Precautions

The following safety precautions should be observed before using
this product and any associated instrumentation. Although some in­struments and accessories would normally be used with non-haz­ardous voltages, there are situations where hazardous conditions
may be present.

This product is intended for use by qualified personnel who recog­nize shock hazards and are familiar with the safety precautions re­quired to avoid possible injury. Read and follow all installation,
operation, and maintenance information carefully before using the
product. Refer to the manual for complete product specifications.

If the product is used in a manner not specified, the protection pro­vided by the product may be impaired.

The types of product users are:

Responsible body is the individual or group responsible for the use

and maintenance of equipment, for ensuring that the equipment is
operated within its specifications and operating limits, and for en­suring that operators are adequately trained.

Operators use the product for its intended function. They must be

trained in electrical safety procedures and proper use of the instru­ment. They must be protected from electric shock and contact with
hazardous live circuits.

Maintenance personnel perform routine procedures on the product

to keep it operating properly, for example, setting the line voltage
or replacing consumable materials. Maintenance procedures are de­scribed in the manual. The procedures explicitly state if the operator
may perform them. Otherwise, they should be performed only by
service personnel.

Service personnel are trained to work on live circuits, and perform

safe installations and repairs of products. Only properly trained ser­vice personnel may perform installation and service procedures.

Keithley products are designed for use with electrical signals that
are rated Installation Category I and Installation Category II, as de­scribed in the International Electrotechnical Commission (IEC)
Standard IEC 60664. Most measurement, control, and data I/O sig­nals are Installation Category I and must not be directly connected
to mains voltage or to voltage sources with high transient over-volt­ages. Installation Category II connections require protection for
high transient over-voltages often associated with local AC mains
connections. Assume all measurement, control, and data I/O con­nections are for connection to Category I sources unless otherwise
marked or described in the Manual.

Exercise extreme caution when a shock hazard is present. Lethal
voltage may be present on cable connector jacks or test fixtures. The
American National Standards Institute (ANSI) states that a shock
hazard exists when voltage levels greater than 30V RMS, 42.4V
peak, or 60VDC are present. A good safety practice is to expect

that hazardous voltage is present in any unknown circuit before
measuring.

Operators of this product must be protected from electric shock at
all times. The responsible body must ensure that operators are pre­vented access and/or insulated from every connection point. In
some cases, connections must be exposed to potential human con­tact. Product operators in these circumstances must be trained to
protect themselves from the risk of electric shock. If the circuit is
capable of operating at or above 1000 volts, no conductive part of

the circuit may be exposed.

Do not connect switching cards directly to unlimited power circuits.
They are intended to be used with impedance limited sources.
NEVER connect switching cards directly to AC mains. When con­necting sources to switching cards, install protective devices to lim­it fault current and voltage to the card.

Before operating an instrument, make sure the line cord is connect­ed to a properly grounded power receptacle. Inspect the connecting
cables, test leads, and jumpers for possible wear, cracks, or breaks
before each use.

When installing equipment where access to the main power cord is
restricted, such as rack mounting, a separate main input power dis­connect device must be provided, in close proximity to the equip­ment and within easy reach of the operator.

For maximum safety, do not touch the product, test cables, or any
other instruments while power is applied to the circuit under test.
ALWAYS remove power from the entire test system and discharge
any capacitors before: connecting or disconnecting cables or jump­ers, installing or removing switching cards, or making internal
changes, such as installing or removing jumpers.

Do not touch any object that could provide a current path to the com­mon side of the circuit under test or power line (earth) ground. Always
make measurements with dry hands while standing on a dry, insulated
surface capable of withstanding the voltage being measured.

The instrument and accessories must be used in accordance with its
specifications and operating instructions or the safety of the equip­ment may be impaired.

Do not exceed the maximum signal levels of the instruments and ac­cessories, as defined in the specifications and operating informa­tion, and as shown on the instrument or test fixture panels, or
switching card.

When fuses are used in a product, replace with same type and rating
for continued protection against fire hazard.

Chassis connections must only be used as shield connections for
measuring circuits, NOT as safety earth ground connections.

If you are using a test fixture, keep the lid closed while power is ap­plied to the device under test. Safe operation requires the use of a
lid interlock.

5/02

If or is present, connect it to safety earth ground using the
wire recommended in the user documentation.

!

The symbol on an instrument indicates that the user should re­fer to the operating instructions located in the manual.

The symbol on an instrument shows that it can source or mea­sure 1000 volts or more, including the combined effect of normal
and common mode voltages. Use standard safety precautions to
avoid personal contact with these voltages.

The WARNING heading in a manual explains dangers that might
result in personal injury or death. Always read the associated infor­mation very carefully before performing the indicated procedure.

The CAUTION heading in a manual explains hazards that could
damage the instrument. Such damage may invalidate the warranty.

Instrumentation and accessories shall not be connected to humans.
Before performing any maintenance, disconnect the line cord and

all test cables.

To maintain protection from electric shock and fire, replacement
components in mains circuits, including the power transformer, test
leads, and input jacks, must be purchased from Keithley Instru­ments. Standard fuses, with applicable national safety approvals,
may be used if the rating and type are the same. Other components
that are not safety related may be purchased from other suppliers as
long as they are equivalent to the original component. (Note that se­lected parts should be purchased only through Keithley Instruments
to maintain accuracy and functionality of the product.) If you are
unsure about the applicability of a replacement component, call a
Keithley Instruments office for information.

To clean an instrument, use a damp cloth or mild, water based
cleaner. Clean the exterior of the instrument only. Do not apply
cleaner directly to the instrument or allow liquids to enter or spill
on the instrument. Products that consist of a circuit board with no
case or chassis (e.g., data acquisition board for installation into a
computer) should never require cleaning if handled according to in­structions. If the board becomes contaminated and operation is af­fected, the board should be returned to the factory for proper
cleaning/servicing.

Contents

CHAPTER

CHAPTER

CHAPTER

1

:

INTRODUCTION

Getting Started
Defautl Mode

RS-232

RS-485

SIOOO

2:

FUNCTIONAL DESCRIPTION

3:

COMMUNICATIONS

Introduction
RS-232C

RS-485

&

Quick Hook-up to a

Software

Single Module Connection
Multi-pany Connection
Software Considerations
Changing Baud Rate
Using A Daisy Chain With A Dumb Terminal

.........................................

RS-485

Communications Delay

.....................................

......................................

RS-485

Quick Hook-Up

.....................................

.......................................

........................................

Multidrop System

1-1

1.1

...........................

RS-232

port

......................

.............................

...............................

..............................

................................

...................

..............................

...............................

1.2

. 1-3

1.4

3.1

3.2

3.2

3.2

3.3

3.4

3.4

3-4

3.5

3.6

CHAPTER

4:

1700

COMMAND SET

Command Structure
Data Structure

Bit

Addresses
Logic Convention
Write Protection
Miscellaneous Protocol
Response Structure
Long Form Responses
Checksum
Command Checksum
Response Checksums
Checksum Calculation

1700

ACKnowledge (ACK)

Assign Input Bit (AIB)

Assign

Assign Output Bit (AOB)

Assign Output Position (AOP)

Assign Input/Output

Clear

Clear Position (CP)

Set Bit (SB)

Set Position

Clear Events

Continuous Input Address (CIA)

Continuous Mode-Change (CMC)

Continuous Mode Disable

........................................

Command

Input

Bit

(CB)

..................................

......................................

......................................

....................................

.....................................

Notes

.............................

...................................

.................................

..................................

.................................

.................................

Set

..................................

................................

................................

Position (AIP)

.............................

..............................

...........................

(AIO)

.............................

....................................

.................................

.....................................

(SP)

..................................

(CE)

..................................

.........................

........................

(CMD)

........................

4.1

4.1

4.2

4.2

4.2

4.3

4.3

4.3

4.4

4.4

4.4

4-4

4.6

4.6

4.7

4.7

4.7

4.7

4.8

4.8

4.8

4.8

4.8

4.9
4-10
4-10
4-10

-v-

Contents

Continuous Mode-Input (CMI)
Continuous Mode-Timer (CMT)

Digital Input
Digital Output
Events Read & Clear (EC)
Identification (ID)
Initial Value
Read Assignment (RA)
Read Assignment Bit (RAB)
Read Assignment Position (RAP)
Read Bit
Read Position (RP)
Read Continuous Mode
Read Continuous Timer (RCT)
Read Input Address (RIA)
Read Data (RD)
Read Identification
Read Initial Value (RIV)
Read Input Sit
Read Input Position (RIP)
Read Setup
Remote Reset

Read Watchdog Timer
Setup Command
Watchdog Timer
Write Enabte

Error Messages

Address Error

Badchecksum.,
Command
Output

Parity Error
Syntax Error
Value Error
Write Protected

(DI)

.................................

(DO)

................................

.................................

(IV)

.................................

..............................

(RB)

...................................

................................

(RCM)

.................................

(RID)

.............................

.............................

(RIB)

...............................

(RSU)

Error

Error

....................................

....................................

................................

(RR)

...............................

(RWT)

(SU)

..............................

(wr)

..............................

(WE)

................................

...................................

...................................

................................

.................................

...................................

...................................

..................................

..........................

.........................

............................

...........................

........................

.........................

.........................

............................

............................

..........................

4-10
4-10

4-11
4-11
4-11
4-12
4-12
4-12
4-13
4-13
4-13
4-13
4-13
4-14
4-14
4-14

4-15

4-15
4-15
4-15
4-16
4-16
4-16
4-17
4-17
4-18
4-18
4-18
4-18
4-19
4-19
4-19
4-19
4-19
4-19

CHAPTER

5:

SETUP INFORMATION

Command Syntax
B~el
Byle2

Bytes

Setup Hints

SlOOO

..........................................

..........................................

Linefeeds

Panty

Baud Rate

B~e3

B~e4

........................................

3

&

4

.......................................

........................................

Echo

.......................................

Delay

........................................

Event Counter Filter

Word Length

.......................................

Software

I

SETUP

COMMAND

...................................

......................................

.....................................

......................................

..............................

..................................

....................................

.

vi-

5-1

5-2

5-3

5-3

5-3
5-4

5-5

5-5

5-5

5-5

5-6

5-6

5-6

5-8

5-9

Contents

CHAPTER

APPENDICES

Appendix
Appendix
Appendix C

6:

A
B

CONTINUOUS lNPUT/OUTPUT

Continuous Output
Continuous Input
Continuous Inputloutput Commands
Continuous Output Trigger Signal
Applications

A) Timer Mode

B)

Timer Mode With Outputs

C) Edge-Trigger Mode With

D)
E)

Change Mode

F)

Change Mode With Multiple Modules

G)

H)

I)

8idirectionaI Continuous InpuVOutput

J)

Multiple Outputs

Continuous

ASCII

Mi770 64
Mi750

.......................................

Continuous Output Daisy-Chain With Host

Continuous Input
Multiple Continuous Input/Output

Input Protocol Notes

Table

Channel

24-Channel

...................................

....................................

..........................

....................................

...........................

Host

..................................

Mode

................................

............................

...........................

I/O

Board

Digital

110

Board

6-1

6.1

.........................

..........................

..................

.....................

.......................

.....................

6.1

-6-2

6.2

6.2

-6-3

6.4

-6-6

6.7

-6-9
6-10
6-12
6-13

6-13

6-14

.

vii

.

Chapter

1

Introduction

The Keithley MetraByte 1700 Series
computer monitoring and control of devices through solid state relays or TTL
signals. The status of inputs and outputs is communicated
format using

With the Keithley MetraByte 1700 series the user can control digital inputs and
outputs individually or all at once. Any channel may be designated as an input or
output by the user. Many industrial applications require a safe start-up condition
to prevent accidents at critical points in the process.The onboard nonvolatile

EEPROM memory stores the user-specified initial condition (input or output)
each channel; thereby eliminating the need
when power is applied

1700 series may be setup in special modes which allow them

The
communicate without being polled by a host computer. Collectively these modes
are called Continuous InpuVOutput Modes. In many applications the burden on
the host may be greatly simplified and in some cases the host may be eliminated

altogether.

The Keithley MetraByte 1700 series include:

M1711/1712

M1750

M1770

Getting

The instructions

use

the MI711 & Mi712 in the figures.

appropriate appendix for instructions on getting started.

RS-232C

<!5

24

64

Started

in

or

RS-485

or

restored.

channel
channel
channel

this chapter cover all

110

I/O

I/O

of

Digital

serial communications.

modules.
board.
board.

110

to Computer Interfaces provide

for

software initialization routines

1700

models; however, for simplicity we

If

you have an M1700 board

to

the host in ASCII

see

of

to

the

Default

All models contain an EEPROM (Electrically Erasable Programmable Read Only
Memory) to store setup information. The
switches necessary
nonvolatile which means that the information
removed.
case.

The EEPROM provides tremendous system flexibility since all of the module's
setup parameters may be configured remotely through the communications port
without having to physically change switch settings. There is one minor drawback
in using €EPROM instead of switches; there
information in the module. It is impossible
the baud rate, address, parity and other settings are. It is difficult to establish
communications with a module whose address and baud rate are unknown.
overcome this, each module has an input pin labeled DEFAULT. By connecting
this pin to Ground, the module

Default Mode.
The Default Mode setup is:
Grounding the DEFAULT' pin does not change any of the setups stored in

EEPROM. The setup may be read back with the Read Setup
determine all of the setups stored
are available.

A

module in Defautt Mode will respond
illegal values (NULL, CR,
command for proper responses. The ASCII vahe of the module address may be

Mode

to

specify baud rate, address, parity, etc. The memory is

No

batteries are used

300

EEPROM

so

it

is never necessary

is

to

tell

is

put in a known communications setup called

baud,

no

panty, any address is recognized.

replaces the

is

retained even if power

no visual indication of the setup

just

by looking at the module what

usual

to

open the module

(RS)

in

the module. In Default Mode, all commands

to

any address except the four identified

$,

#).

A dummy address must be included in every

array

of

is

To

command to

1-2

1700

USERS

MANUAL

read back with the

is

to deliberately generate an error message. The error message outputs the

module's address directly after the
Setup information in a module may be changed at will with the Setup (SU)

command. Baud rate and parity setups may

Default values of
the module automatically performs a program reset and configures itself to the
baud rate and parity stored in the setup information.

The Default Mode
terminal

most cases, a module in Default Mode may not be used in a string with other

modules.

RS-232

Software is
you begin to get familiar with the module by setting it up on the bench.

using a
connections shown in the quick hook-up drawings, Figures

module in the Default Mode by grounding the Default' terminal. Initialize the
terminal communications package on

mode. Since this step vanes

manual

Begin by typing

respond with an
you have a response from the module you can turn to the Chapter
familiar with the command

or

computer for the purpose of identifying and modifying setup values. In

8

not

dumb

for

instructions.

RS

command. An easy way

'?

prompt.

300

baud and no parity. When the DEFAULT* pin is released,

is

intended to be used with a single module connected

RS-485

required to begin using your

terminal

Quick

or

$1DI

and pressing the Enter

*

followed by the data reading at the input, typically

Hook-Up

a

computer that acts like a dumb terminal. Make the

your

from

computer to computer, refer

set.

to

determine the address character

be

changed without affecting the

M1700

computer

module. We recommend that

to

or

Return key. The module will

1.1

or

put

it

into the "trminal"

to

your computer

Start

1.2.

8000.

4

and get

to

a

by

Put the

Once

All modules are shipped from the factory with a setup that includes a channel

address
delay. Refer

of

1,

300

baud fate, no linefeeds, no parity, no echo and two-character

to

the Chapter 5 to configure the module to

+

10

to

+30

Ydc

Power

Supply

-0

+Q

1

b

A

-

@

&,

8
8

Q

@

8

8

3

your

BB2

301

800'EY

DEFAULT*

TRRNSMIT

RECEIYE

I+vs

I

application.

M1711

DiGITRL

L'O

R.--pZC

9005

607

608

609

BBR

B0B

Figure

1.1

RS-232

Quick Hook-Up.

Introduction

*

B04

BE

B03

1802

BBC

BBD

1-3

Figure

RS-485

An
evaluation purposes. This connection
should never be used for a permanent installation. Figure
up.

limited to

All

requirement. With this connection, characters generated
echoed back.
be turned off.

If

to

1.2

RS-485

Quick

RS-485

This

connection

less

terminals that

the current limiting capability

lkC2

resistor in series with the

Quick Hook-Up.

Hook-up

module may be easily interfaced

will

than

50mA

use

To

avoid double characters,

to

work provided the

and the

1488 and 1489 style interface

a

RS-232

RS-232C

of

the

RS-232

port

to

an

RS-232C

is

only suitable for benchtop operation and

RS-232C

receive threshold is greater than

the

RS-232C

output.

local echo

output is uncertain, insert a

transmit output

terminal for

1.3

shows

IC’s

by

the terminal will be

on

the terminal should

will

satisfy this

the hook-

is

current

OV.

1

OOR

1-4

1700

USERS

MANUAL

Figure

1.3

SlOOO

Software

S1000

software

RS-485

Software

is

available

tuns

Quick

Hook-Up

to

assist the user

on

the

IBM

compatible

with

an

RS-232

in

setting

Pc's

up

and

Port.

the

1700

is

available free

modules. The

of

charge.

Chapter

2

Functional Description

The Keithley MetraByte
monitoring of on-off signals in response to simple commands from
computer. Digital commands are transmitted to the

RS-232

form of simple English ASCII character strings for ease of use. The ASCH protocol
allows the units
intelligent controllers and computers.

or

RS-485

to

MI700

communications links. Commands and responses are in the

be interfaced with dumb terminals and modems as well as

Digital

I/O

modules provide remote control and

Mi700

units using standard

a

host

-

DATA

DATA*

RS-485

INTERFACE

EEPROM

TRANSMIT

\

RECE~YE

\

-

MICRO-

PROCESSOR

OUTPUT

-

DRIVERS

H

t

EVENT

COUNTER

F

(10

TO

30V)

Figure
Figure

microprocessor is used
the bi-directional
the host computer through a serial communications
communications components are used

485

thoroughly checked for syntax and data errors. Valid commands are then
processed
available to configure and control the digital
commands are then produced

host over the
An Electrically Erasable Programmable Read-Only Memory (EEPROM) is used to

retain important data even
contains setup information such

I/O configuration data.

2.1

Digital

I/O

Functional Block Diagram.

2.1

shows a functional block diagram

to

provide

I/O

lines. The microprocessor receives commands and data from

communications standard. Commands received

to

complete the desired function. A wide variety

by

RS-485

serial

link.

if

Y+

>-I

GND

I

an

intelligent interface between the host and

to

interface the microprocessor

I/O

the microprocessor and transmitted back to the

the module is powered down. The EEPROM

as

the address, baud rate, and parity as well as

POWER

of

a

M1712.

by

the microprocessor are

lines. Responses

An &bit

port.

of

commands are

I

CMOS

Specialized

to

the

RS-

to

the host

2-2

1700

Each digital line on the

by

the user to be an input or an output. The direction assignments of all the lines

are stored in

the

M1712

USERS

EEPROM

is powered up.

MANUAL

M1712

so

is bidirectional and may be individually configured

that the lines are automatically configured each time

+5Y

1

DDK

crp

INPUT

w

OUTPUT

Figure
Figure

darlington circuit capable

30V.

package is
resistors are not provided in the modules.

When the
input state is read by the microprocessor through an input protection circuit
consisting of a
from 0 to
driver off, the
than

2.2

The maximum total current that may be handled by

+5V.

<

\

I

Digital

2.2

is

a detail diagram

IA.

110

pin is configured

1

30V

without damaging the microprocessor.

lOOK

v

I/O

Circuit.

of

of

sinking

a single

110

200mA

line circuit. The output driver

with a maximum output voltage

the

The output saturation voltage at

as

an input,

OOK

resistor and diodes. This allows the input values

200mA

the

output driver

is

Note

resistor produces a leakage current

if

the

I/O

BIT

GND

is

a

of

MI711

1.2V

is

that with the output

I/O

or

M1712

max. Pullup

turned

off.

The

to

range

line is greater

When a read function
is read back even
verify the state of the output.

is

performed on an

if

the pin is configured as

I10

pin, the actual logical state

an

output. this provides a means to

of

the pin

Functional Description

2-3

AC

-

BOO

B01

figure
Figure

relays. When electromechanical relays are used, always include a flyback diode to
avoid damage

2.3

Digital Outputs Used With Relays.

2.3

shows typical connections

to

the output driver.

8

1

N400

8

-

to

solid-state relays and electromechanical

-

+Ys

1

-

+5Ydc

PP

EVENT

COUNTER

1

OOpF

lOOK

+5VdC

PP

INPUT

Figure
Figure

pins but it has the event counter circuitry added on. The event counter circuitry

consists
filtering. The event data

event signal

2.4

Events Counter Circuit.

2.4

is a detail schematic

of

input protection components and a capacitor to provide some noise

is

to

the rnicroprosser.

,

\

of

the BOOlEV pin. This pin is identical to all other

buffered

by

a Schmitt-trigger gate which outputs

lOOK

the

BB0/EV

2-4

1700

The microprosser contains a user-programmable
counter input. The filter is necessary when the event signal is derived from
mechanicat contacts such
selectable for
setting

.

USERS

0,520

MANUAL

as

switches or relays. The filter constant is user-

or

50ms.

Figure

filter

to

2.5

shows the filter action

debounce the event

for

the 5ms

EYENT

SAMPLE

FILERED

Figure

The microprosser samples the event input

be high for at least five consecutive samples before it will be counted as a high
transition. Similarly, the input must be low for five sample periods before it is
counted as a low signal.
consecutive samples, etc.

The last
converts the

in the module.

EEPROM.

RS-232

COUNTER

CLOCK

SIGNAL

2.5

Event Counter Debounce Filter.

major

raw

On

communications standard.

H

block

10

to

It

produces

RS-232

If

the filter

in the diagram is the power supply. The power supply

30

volts supplied by the user into regulated voltages used

+5V

units, the power supply produces

at

is

set for

necessary

lrns

intervak. The input signal

20ms,

the input must be stable for

to

operate the microprocessor and

fl

OV

necessary for the

must

20

Chapter

3

Communications

Introduction

The M1700 modules have been carefully designed to be easy to interface to all
popular computers and terminals. All communications
are performed with printable ASCII characters. This allows the information to be
processed with string functions common to most high-level languages such as
BASIC. For computers that support RS-232C, no special machine language
software drivers are necessary for operation. The modules can be connected to
auto-answer modems for long-distance operation without the need for
supervisory computer. The ASCII format makes system debugging easy with a
dumb terminal.

The Keithley MetraByte system allows multiple modules to be connected to a

a

communications port with
strung together on one cable;
units is about ten, although a string of 124 units is possible. The modules
communicate with the host on a polling system; that is, each module responds to
its own unique address and must be interrogated by the host.
never initiate a communications sequence.
protocol must be strictly observed
errors.

single 4-wire cable. Up to

124

with repeaters. A practical limit for RS-232C

to

avoid communications collisions and data

to

and from the modules

32

RS-485

A

simple command/response

modules may be

A

module can

a

Communication
ASClf command codes such as
all commands

would

look like this:

Command:

Response:

A commandlresponse sequence is not complete until a valid response is
received. The host may not initiate a new command until the response from
previous command is complete. Failure to observe
communications collisions. A valid response can be in one of three

1) a normal response indicated by a ' prompt

2)

3)

When a module receives a valid command, it must interpret the command,
perform the desired function, and then communicate the response back to the
host. Each command has an associated delay time
calculating the response.
appropriate amount
error has occurred. After the communications time-out
response data

to

the M1700 modules is performed with two- or three- character

DO

for Digitai Output. A complete description of

is

given in the Chapter

$1

RD

*+99999.99

an error message indicated by a
a communications time-out error

If

the host does not receive a response in an

of

time specified in Table

is

forthcoming. This error usually results when an improper

4.

A

typical commandlresponse sequence

this

' ? '

prompt

in

which the module is busy

3.1,

a communications time-out

it

a

rule will result in

forms:

is assumed that no

3-2

1700

USERS

MANUAL

command prompt
specification for each command:

Mnemonic

ACK,

CB,

CE, CP, DI,

RD,RP,

EC,

AOP,

W,
Table
The timeout specification is the turn-around time from

to

RS-232

RS-232C

transfer between computing equipment.

will

Although the
equipment to a computer, the Keithley MetraByte system allows
modules to be connected in a daisy-chain network structure.The advantages
offered by the

However,

RS,

RE,

RW,

CIA,

CMC, CMD,

CT,

SU,

3.1

Response Timeout Specifications.

when the module starts to transmit a response.

C

is the most widely used communications standard for information

interface

1)

widely used by all computing equipment

2)

no additional interface hardware in most cases

3)

separate transmit and receive lines ease debugging

4)

compatible with dumb terminals

RS-232C

1)

low noise immunity

2)

short usable distance

3)

maximum baud rate

4)

greater communications delay in multiple-module systems

5)

less reliable-loss

6)

wiring is slightly more complex than

7)

host software must handle echo characters

or

address is transmitted. The table below lists the timeout

Timeout

I

5.0

DO,

RA, RAB,

RSU,

SB,

SP,

RIA,

RID,

RIV,

RCT,

CME,

CMT

AIO,

ID,

IV

to

virtualIy all popular computers without any additional hardware.

RS-232C

standard

RAP,

RB,

RCM,

RR,

WE

AtB, AIP, AOB,

RS-232C

is

designed

the

receipt

versions of the

to

connect a single piece

ms

115.0

I

100

of

a

1700

ms

ms

command

for

RS-232C

standard are:

suffers from severaI disadvantages:

-

50

to

200

feet

-

19200

of

one module breaks chain

RS-485

Series

of

several

Single

Figure

the Default Mode to enter €he desired address, baud rate, and other setups (see

Setups). The use

communications line.

Multi-party

RS-232C

modules can be daisy-chained
communications port. The wiring necessary to create the daisy-chain is shown in
Figure
Receive input of the next module in the daisy chain. This wiring sequence must
be followed until the output
input
and must echo all received data (see Setups). Each module must be setup with
its own unique address to avoid communications collisions (see Setups). In this
network, any characters transmitted by the

the chain and passed on to the next station until

to the Receive input of the host. In this manner all the commands given by the

Module

1.3

shows the connections necessary to attach one module

Connectlon

of

echo is not necessary when using a single module on the

Connection

is not designed

3.1.

Notice that starting with the host, each Transmit output

of

the host.

All

to

be used in a multi-party system; however the MI

to

allow many modules

of

the last module in the chain is wired to the Receive

modules in the chain must be setup to the same baud rate

host

to

are received by each module in

the

information

to

a host. Use

700

be connected to a single

is

wired to the

is

echoed back

Communications

3-3

host are examined by every module.
addressed and receives
response
any other modules in the chain until it reaches its final destination, the Receive
input

on

of

the host.

the daisy chain network. The response data will be rippIe through

Figure

a

valid command, it will respond by transmitting the

3.1.

RS-232

If a module in the chain is correctly

Daisy

Chain

Network

The daisy chain network must be carefully implemented

inherent in its structure. The daisy-chain is a series-connected structure and any
break in the communications link will bring down the whole system. Several rules
must be observed to create a working chain:

1.

All

wiring connections must be secure; any break in the wiring,

power, ground or communications will break the chain.

2.

All

modules must be plugged into their connectors.

3.

All

modules must be setup for the same baud rate.

4.

All

modules must be setup for echo.

Software Considerations

If

the host device is a computer, it must be able

messages on its Receive input along with the responses from the module. This

can be handled by software string functions by observing that a module response

always begins with

A

properly addressed

characters in the command including the terminating carriage return. Upon

receiving the carriage return, the module will immediately calculate and transmit

the response

characters that appear on its receive input. However,
during this computation period, it will be stored in the module's internal receive

buffer. This character will be echoed after the response string is transmitted by
the module. This situation will occur
character on the command carriage return. In this case the linefeed character wilt

be

echoed after the response string has been transmitted.

a

' * '

or

'

'?

'

character and

M1700

to

the command. During this time, the module will not echo any

module in a daisy chain will echo

if

the host computer appends a linefeed

to

handle the echoed command

ends

with a carnage return.

to

avoid the pitfalls

if

a character

all

of

is

received

the

The daisy chain also affects the command timeout specifications. When a module

in the chain receives a character it
through the module's internal WART. This method is used to provide more

is

echoed

by

re-transmitting the character

3-4

1700

reliable communications since the UART eliminates any slewing errors caused by
the transmission lines. However, this method creates a delay in propagating the
character through the chain. The delay

retransmit one character using the baud rate setup in the module:

USERS MANUAL

is

equal

to

the time necessary

to

Baud Rate

300

600

1200

240

0

4800

9600

19200

38400

One delay time is accumulated for each module in the chain. For example, if

modules are used in a chain operating at 1200 baud, the accumulated de[ay time

is

4

X

8.33

mS

=

33.3 mS This time must be added to the times listed in Table 3.1

to calculate the correct communications time-out error.

For

modules with RS-232C outputs, the programmed communications delay
specified
character

results in a delay of
setup data, this sequence is repeated. Programmed communications delay is
seldom necessary in an

adds one character of communications delay.

Changing

It is possible to change the baud rate
process must be done carefully to avoid breaking the communications link.

in

the setup data (see Chapter

(00)

followed by an idle line condition for one character time. This

two

character periods. For longer deIay times specified in the

Baud Rate

Delay

33.30mS

16.70mS

8.33111s

4.17mS

2.08mS

1.04mS

RS-232C

520pS

260pS

four

5)

is implemented by sending a

daisy chain since each module in the chain

of

an RS-232C daisy chain on-line. This

NULL

1.

Use the Setup
module in the chain. Be careful not to generate a reset during this process.
reset can be caused by the Remote Reset

2. Verify that all the modules in the chain contain the new baud rate setup

using the Read Setup

for

the same baud rate.

3.

Remove power from all the modules for at least

to

power

loads in the new baud rate.

the new baud rate.

Using

A

dumb terminal can be used to communicate to a daisy-chained system. The
terminal is connected in the same manner as a computer used as
commands typed into the dumb terminal will be echoed by the daisy chain.
avoid double characters when typing commands, set the terminal to full duplex

mode or turn off the loca[ echo. The daisy chain will provide the input command

echo.

RS-485

RS-485 is a recently developed communications standard
multidropped systems that can communicate at high data rafes over long
distances.

wires switching from

the modules. This generates a power-up reset in each module and

4.

Change the host baud rate

5.

Be sure

A

to

Daisy-Chain With

RS-485

(SU)

command to change the baud rate setup on each

A

(RR)

command

(RS)

command. Every module in the chain must be setup

to

the new value and check communications.

compensate for a different communications delay as a result of

A

is similar

0

to

5V

Dumb

to

RS-422 in that it uses a balanced differential pair of

to

communicate data. RS-485 receivers can handle

Terminal

or

power interruptions.

10

seconds. Restore

a

host. Any

to

satisfy the need

To

for

Communications

3-5

common mode voltages from -7V
for transmission over great distances.
balanced pair of wires for both transmitting and receiving. Since an
system cannot transmit and receive at the same time
system.

RS-485

support for this new standard. Interface boards are available for the
compatibles and other
gains popularity. An

Keithley MetraByte offers interface converters to convert
These converters also include power supplies to power up to
MetraByte modules.
are available from Keithley MetraByte to string up to
communications port.

RS-485

1)

2)

3)

4)

5)

6)

7)

8)

does have disadvantages. Very few computers

offers many advantages over

balanced line gives excellent noise immunity

can communicate with Keithley MetraByte modules at

communications distances up to

true multidrop; modules are connected in parallel

individual modules may be disconnected without affecting

other modules

up to

32

modules on one line;
no communications delay due to multiple modules
simplified wiring using standard telephone cable

RS-485

RS-485

To

expand an

to

+12V

without

RS-485

124

equipment will become available as the standard

system usually requires an interface.

RS-485

loss

of

data, making them ideal

differs from

RS-232C:

10,000

feet.

with repeaters

system even further, repeater boxes

RS-422

it

is

inherently a halfduplex

or

terminals have built-in

RS-232C

124

by using one

38400

IBM

to

32

modules

RS-485

baud

PC

RS-485.

Keithley

on

one

and

RS-485

Figure
Notice that every module has

of

modules may be unplugged without affecting the remaining modules. Each
module must be setup with a unique address and the addresses can be in any
order. All
Setup). Also note that the connector pins
notations
telephone cable:

This

cable
guarantee correct installation.

DATA* on the label is the complement

To

arranged

of

the transmission line should be avoided. For wire
total, each end of the line should be terminated with a
between DATA and DATA*.

Multidrop System

3.2

illustrates the wiring required for multiple-module

a

direct connection to the host system. Any number

RS-485

(B),

!Ax!

(B)

GND

(R)

v+

(v)

DATA Yellow

color convention is used

is

used,

minimize unwanted reflections on the transmission line, the bus should be

as

modules must be setup for no echo

(R),

(G), and

(Y).

This designates the colors used on standard 4-wire

on

to

avoid bus conflicts (see

each module are labelled with

LUcx

Black

Red

Green (G) DATA*

to

simplify installation.

it

is only necessary

a line going from one module to the next. 'Tree' or random structures

to

match the labeled pins with the wire color to

of

DATA (negative true).

If

standard 4-wire telephone

runs

220Q

RS-485

greater than

resistor connected

system.

500

feet

When using
time when all stations on the line are in receive mode. During this time, the
communications lines are left floating and are very susceptible

a

bi-directional

RS-485

system, there are unavoidable periods of

to

noise. To

3-6

1700

USERS

MANUAL

prevent the generation
MARK condition as shown in Figure

DATA line more positive than the DATA* line when none

transmitters are on. When enabled, the

overcomes the load presented
Special care must be taken with very long busses (greater than

ensure error-free operation. Long busses must be terminated as described
above. The use of twisted cable for the DATA and DATA* lines will greatly
enhance signal fidelity. Use parity and checksums along with the
commands
used on
consideration. The GND wire is used both as
common reference for the transmission line receivers in the modules. Voltage
drops in the
receivers are rated
operation, the common mode voltage should be kept below

To avoid problems with voltage drops,

than transmitting the power from the host. Inexpensive 'calculator' type power

supplies are useful
provide a ground reference with a third wire to the host or through a good earth
ground. With local supplies and an earth ground, only two wires for the data
connections are necessary.

to

detect transmission errors. In situations where many modules are

a

long line, voltage drops in the power leads becomes an important

GND

Communications

All Keithley MetraByte modules with
provide

(see Chapter

a carriage return as a carriage return-linefeed string. Without the delay, the

linefeed character may collide with the first transmitted character from the module,
resulting in garbled data.

single character, the delay may be set to zero to improve communications

response time.

two

units

5).

This delay is necessary when using host computers that transmit

of

random characters, the lines should be biased in a

3.2.

The

1

K

resistors are used

low

impedance of an

by

the resistors.

a

power connection and the

leads appear as a common-mode voltage to the receivers. The

for

a maximum

of

-7V. of common-mode voltage. For reliable

RS-485

lo

keep the

of

the

driver easily

1000

'#'

form

RS-485

feet) to

of

all

-5V.

modules

in

remote locations. When local supplies are used, be sure to

Delay

RS-485

of

communications delay after

If

the host computer transmits a carriage return as a

may be powered locally rather

outputs are setup at the factory to

it

command has been received

0

+SY

IKn

B

=

Black

R

=

Red

G

=

Green

Y

=

Vellow

7

up

to

10,000

Feet

4

HOST

RS485

+10

to

40Ydc

+VS

+

-

-

I

EARTH

GROUND

(R)

-

-

220n

1Kn

7

Figure

3.2

RS485Netwok.

Chapter

1700

The M1700 modules operate with a simple commandlresponse protocol to
control all module functions.
the host computer or terminal before the module
module can never initiate a communications sequence (unless
Continuous Output Mode (see Chapter
exploit the full functionality of the modules. A list of available commands and a
sample format

for

each command

A

command must be transmitted to the module by

will

respond with useful data. A

6).

A

variety of commands exists

is

listed in Table 4.1.

Command

it

is setup for

4

Set

to

Command

Each command message from the host must begin with a command prompt

character

two

valid prompt characters; a dollar sign character
response message
data necessary to complete the command. The second prompt character
pound sign character
format will be covered a little later).

The prompt character must be followed by a single address character identifying
the module
common communications port must be setup with
commands may be directed
by the user
ASCII characters such as '1' (ASCII
address characters.

The address character is followed by a two
identifies the function
commands are listed in Table
commands are described in full later in this section. Commands must be
transmitted

A

two-character checksum may be appended

option. See 'Checksum' section below.
All commands must be terminated by a Carriage Return character (ASCII

all

command examples in this text the Carnage Return is either implied or denoted

by the symbol 'CR'.)

Structure

to

signal to the modules that a command message

($)

from

the module. A short response

(#)

which generates

to

which the command is directed. Each module attached to a

long

responses (the long response

its

to

the proper unit. Module addresses are assigned

with

the Setup

as

upper-case characters.

(SU)

command.

$31)

to

be performed by the module. All of the available

4.1

along

or

For

ease in debugging, printable

'A'

(ASCII

or

with

to

$41)

three character command which

a short function definition.

any command message as a user

is

to

follow. There are

is used to generate a

is

the minimum amount of

own unique address

are the best choices for

short

is

the

so

that

All

$00).

(In

Data Structure

Many commands require additional data values

definition as shown in the example commands in Table

for

necessary

descriptions.
The majority

hexadecimal (base 16) numbers representing digital data. Each hexadecimal

ASCII

digit represents four bits of digital data. For example:

(binary)

An

example command may

Command:

these commands

of

data values used with the M1700 series

$1

DOFFFF

look

is

described in full in the complete command

like this:

to

complete the command

4.1.

The particular data

is

in the form

E5

(hex)

=

11

10

of

0101

4-2

1700

USERS

MANUAL

This is an example of the Digital Output
would be used to turn on

Data read back from the Event Counter with the Read Events

the form

of

a sevendigit decimal number. For example:

Command:
Response:

Analog data is represented in a form of sign, five digits, decimal point and two

additional digits:

Command:

Response:

The analog data format is used with the

Bit

Addresses

There are several commands that are used to manipulate a single bit. These
commands require a bit address
correct
format and the Position format.

The Bit format specifies the desired

number preceded by the letter

I/O

line. Bit addresses may be specified in

Command:

16

bits of data represented by

$1

RE

*0000123

$1 RWT

*+00010.00

'B.

$1

SSOF

(DO)

command. This particular command

'FFFF'.

(RE)

command

Wr

and CT commands.

so

that the desired action will be directed to the

two

different formats, the Bit

t10

line using a two-character hexadecimal

For example:

is

in

This is an example

to the address

The Position format uses a decimal address preceded by the letter
example:

Command:

This is an example of the Set Position (SP) command. The command action
directed to the
examples produce the same results. The choice
notation is

strictly

of

the Set Bit

OF

(hexadecimal).

$1SP15

I/O

line address

a matter of user preference.

(SB)

command. The command action is directed

15

(decimal). Note that the last

'P.

two

command

of

the Bit notation or Position

For

is

Logic Convention

Most devices in the
interface directly with solid-state relays. The control input of the relay is generally
connected between the output line and a source of power. With conventional

relays, the output transistor is turned on to sink current through the relay, turning
the relay on. The logic convention used in the
to turn on the relay. This means that the output voltage measured at the
will be near ground potential

The logic convention used to read input data

'high' voltage potential at the

potential will be read back as a logical

M1700

(low).

family feature open-collector transistor outputs to

MI700

This is an example

is

I/O

line will be read back as a logical

'0'.

series requires a logical

I/O

line

of

negative logic.

positive logic. This means that

'3'.

A

'1'

a

low

Write Protection

Many

of

the commands listed
Protected Commands'. These commands are used to alter setup data in the
module's

EEPROM.

These commands are write protected to guard against

in

Table

4.1

are under the heading

of

'Write

1700

Command

Set

4-3

accidental
a Write Enable

loss

of

setup data. All write-protected commands must be preceded

(WE)

command before the protected command may be executed.

by

Miscellaneous Protocol Notes
The address character must transmitted immediately after the command prompt
Character. After the address character the module will ignore any character below
ASCII

$23

(except, of course,

within the command message for better readability
The length

of

a command message is limited to

properly addressed module receives a command message

CR).

This allows the use of spaces (ASCII

if

desired.

25

printable characters.

of

more than

$20)

If

a

25

characters the module will abort the whole command sequence and no response
will result.

If

a properly addressed module receives a second command prompt before

receives

a

CR,

the command wili be aborted and no response will result.

it

Response Structure
Response messages from the
(ASCII $2A) or a question mark
acknowledgment of a valid command. The
All response messages are terminated with
single

'*'

character

to

acknowledge that the command has been executed by the

module. Other commands send data information following the

M1700

'?'

(ASCII

module begin with either an asterisk

$3Fj

prompt. The

'?'

prompt precedes an error message.

a

CR. Many commands simply return a

'*I

prompt indicates

I*'

prompt. The

'*I

response format of all commands may be found in the detaiIed command
description.

The maximum response message length is

25

characters.

A command/response sequence is not complete until a valid response is
received. The host may not initiate a new command until the response from a
previous command is complete. Failure to observe this rule will result in
communications collisions.

1)

a normal response indicated by a

2)

an error message indicated by a

3)

a communications time-out error

A

valid response can be in one

' * '

prompt

' ? '

prompt

of

three forms:

When a module receives a valid command, it must interpret the command,
perform the desired function, and the communicate the response back
host. Each command has an associated delay time in which the rnodute
calculating the response.
appropriate amount of time specified in Table

If

the host does not receive a response in an

3.1,

a communications time-out

to

is

the

busy

error has occurred. After the communications time-out it is assumed that no
response data is forthcoming. This error usually results when an improper
command prompt or address

Long Form
When the pound sign

Responses

' # '

is

transmitted.

command prompt is used, the module will respond with
a 'long form' response. This type of response will echo the command message,
supply the necessary response data, and
the end

of

the message. Long form responses are used in cases where the host
wishes to verify the command received by the module. The checksum
to verify the integrity of the response data. The

will

add a two-character checksum

'

#

'

command prompt may be

is

included

to

used with any command. For example:

Command:
Response:

$1

DI

*a000

(short

form)

4-4

1700

USERS

MANUAL

Command:
Response:

For the

Mi700

#I

DI

'1

D18000BO

(Iong form)
(BO=checksurn)

commands that affect the digital outputs, the

'#'

form of a
command starts a handshaking sequence fhat must be terminated with an
Acknowledge (ACK) command. (See ACK command)

Checksum

The checksum is a two character hexadecimal value appended

message. It verifies that the message received is exactly the same

to

the end

as

of

the

a

message sent. The checksum ensures the integrity of the information

communicated.

Command Checksum

A two-character checksum may be appended to any command to the

module
two extra characters and assumes that it is a checksum.
present, the module will perform the command normally.

as

a

user option. When a module interprets a command, it looks

If

the checksum is not

If

the two extra

characters are present, the module will calculate the checksum for the message.

M1700

for

the

If

the calculated checksum does not agree with the transmitted checksum, the

moduIe will respond with a 'BAD CHECKSUM' error message and the command
will be aborted.

module receives
and the command will

Command:
Response:

If

the checksums agree, the command will be executed.

a

single extra character, it will respond with a 'SYNTAX

be

$1

DI

*

8 0 0 0

aborted.

For

example:

(no

checksum)

If

the

ERROR

Command:
Response:

Command:
Response:

Command:
Response:

$1

DIE2

*8000

$1

DtAB

?1

BAD

$1

DIE

?i

SYNTAX

(with checksum)

(incorrect checksum)

CHECKSUM

(one extra character)

ERROR

Response Checksums

If

the long form

' # '

version of a command is transmitted to a module, a checksum

will be appended to the end of the response. For example:

Command:
Response:

Command:
Response:

$1

DI

*8000

#i

DI

'1

D18000BO

(short form)

(Iong form)

(BO=c hecksum)

Checksum CaIculation

The checksum is calculated
characters in the message. The lowest order
as the checksum. These two digits are then converted
equivalents and appended

the form

of

printable characters.

Example: Append a checksum to the command

by

summing the hexadecimal values of

two

hex digits

to

to

the message. This ensures that the checksum is

#1

DOFF00

all

the

ASCII

of

the

sum are used

their ASCII character

in

1700

Command

Set

4-5

Characters
ASCII hexvalues:

Sum (hex addition)

The checksum is
to the end of the message:

Example: Verify the checksum of a module response

The checksum is the two characters preceding the

:

#lDOFFOO

23 31
23 + 31

44

4F 46

+

44

+

D3

(hex). Append the characters D and

#1DOFFOOD3

4F

+

46

46

+

30

46

30

+

30

+

'1

30

=

1

D3

3

D18000BO

CR:

SO

Add the remaining character values:

*1

2A+

The two lowest-order hex digits

31+

44+

DI

80

49+

38+

00

30+

30i

of

30=

the

1BO

sum are

BO

which agrees with the

transmitted checksum.

Note that the transmitted checksum is the character string equivalent

calculated hex integer. The variables must be converted

to

software

If

checksums do not agree, a communications error has occurred.

If

a module is setup

in

the checksum calculation.

determine equivalency.

to

provide linefeeds, the linefeed characters are

to

like types in the host

to

the

not

included

Panty bits are never included in the checksum calculation.

Table

Command Definition

4.1.

1700

Command

Set

Typical

Command
Message

ACK

CB
CP

DI
DO

RA

RAB

RAP

RB

RD

RE

RID

RIV

RP

RS

RSU

RWT

SB

SP

WE

Acknowledge
Clear Bit
Clear Position

Digital Input

Digital Output

Read

Assignments
Read Assignment Bit
Read Assignment Pos.

Read

Bit

Read

Data

Read Event Counter
Read Identification
Read Initial Value
Read Position
Read Setup
Read Setup
Read Watchdog Timer
Set Bit
Set Position

Write Enable

$lACK

$1

CBOC

$1

CPI

2

$1

DI

$1

DO1 234

$1

RA

$lRABOl

$lRAPOl

$1

RBOF

$1 RD
$1

RE

$1

RID

$1

RIV

$1

RP15

$1

RS

$1

RSU

$1

RWT

$1

SBOC

$1SP12

$1

WE

Typical

Response

Message

*

*

'8007

f

*OFOF

*O

*I

'1

*+99999.99

'0001 234

'BOILER

'OFOF

'0

'31

070j 02

'31

0701

02

*+00010.00

.

t

4-6

1700

USERS

MANUAL

The following 1700 commands are Write Protected
AIB Assign Input Bit $lAIBOF

AIO

AIP Assign Input Position $1 Alp1

Assign InpuWOutput $1AIOOFOF

5

A03 Assign Output Bit $lAOBOF
A0

P

CE Clear Event Counter

EC

ID

IV

RR

su

wr

The following

Assign Output

Pos.

$1

AOPl5

$1CE

Event Read & Clear
Identification
Initial Value $1
Remote Reset $1
Setup

$1

EC

$1

IDBOILER
[VOFOF

RR

$1

SU31070102

Watchdog Timer $1 WT+00010.00

1700

commands are used with the special Continuous

InpuVOutput Modes:
CIA Continuous Input Address $1CIA31
CMC Continuous Mode-Change $1CMC
CM

D

CME Continuous Mode-Edge $1

Continuous Mode Disable $lCMD

CME

CMI Continuous Mode-Input $lCMl
CMT Continuous Mode-Timer

CT Continuous Timer

RCM Read Continuous Mode $1

RCT

R

[A Read Input Address $1 RIA

Read Continuous Timer $1 RCT

$1

CMT

$1

CT+00010.00

RCM

t

*

t

t

t

t

'0001

t

t

t

t

t

t

t

t

*

'D

'+OOO
'31

234

10.00

1700

ACK no

Command

w

I

ed

g

e

Set

(A CK)

The ACKnowledge command is a hand-shaking command that may be used with
any command that will affect the the digital outputs such as the Digital Output

(DO)

command.

level

of

data security to guard against transmission errors when performing output

functions

Command:

Response:

.

It

is used to confirm the data sent to a module and adds another

$1

ACK

*

Command: #lACK

*1

Response:

The ACK command is used in conjunction with the
command.

For

example:

Command:

Response:

Note that the command is echoed back with a checksum

any time the

'#'

ACKSA

#lDOFFFF

'1

DOFFFF06

prompt is used. However, in the case

'#'

form

of

an output

(06)

which is the case

of

the DO command, the
output data has not been changed at this point. The command data is echoed
back

so

that the host may verify that the correct message has been received by

the module.

activate

If

the command data

the

command by issuing

is

confirmed

an

ACK

to

command:

be correct, the host may then

Command: $lACK
Response:

*

Only

at

this point will the outputs be affected by the

If

the host detects an error in the response data,

repeating the original command. For example:

1700

DO

it

Command

command.

may recover by simply

Set

4-7

Command:
Response:

In ths case the response data does
that the module may have received the command incorrectly due to noise
transmission line. However, the erroneous data does
the module must receive an ACK to complete the command. To correct the error,
the

host

may re-issue the original command:

Command:
Response:

This time the response data is correct, and the
by sending the acknowledgement:

Command:
Response:

Commands that require ACK handshaking are: AIB,
CP,

DO,

SB,

and

An ACK command used without an associated output command will generate a

COMMAND

Assign Input
Assign Input Position
Assign Output Bit
Assign Output Position (AOP)
The Assign Input and Assign Output commands are used
direction
individual bit
commands configure data bits

ERROR.

of

an individual

to

#I

DOFFFF

*1

DOFFFE05

#lDOFFFF

*1

DOFFFFO6

$IACK

*

SP.

Bit

(AIB)

(AIP)

(AOB)

110

line. The Assign Input commands configure an

be used as an input

to

be outputs

not

match the original command, indicating

on

not

reach the output since

DO

command may be completed

AIO,

Alp, AOB, AOP,

to

specify the data

to

read external signals. The Assign Output

to

control external equipment.

the

CB,

This

command configures

Command: $1AOB05

Response:

This command configures Bit

Command:
Response:

When used with
command from the

Command:
Response: *jAIBOCSA

Command:
Response:

the

host

Bit

*

$1

AlBOC

*

'#

prompt, the Al and

to

compiete the bit assignment:

#lAIBOC

$1

ACK

*

05

to

be an output:

OC

to be an input:

A0

commands require an ACK

4-8

1700

(See Acknowledge (ACK) command for more detail)

The Assign Input Position (AIP) and the Assign Output Position commands
operate in the same manner as the
positions are specified in decimal (base

All

of

must be preceded by a Write Enable

The

110

EEPROM

powered up.

Assign Input/Output (AlO)
The Assign InpuVOutput
of

all data lines at once. The direction data is represented in hexadecimal
notation. A logical
logical

according to the number
the device (see Setup section).

This command configures

USERS

the Assign commands alter the contents

direction assignments altered by the Assign commands are saved in

so

that all pin directions are automatically configured when the device

'0'

specifies a data input. The length of the hex data argument

MANUAL

(AIO)

command is used to configure the data direction

'1'

indicates that an

of

VO

lines available and the word length that is setup in

16

bits of

AIB

and

AOB

command except that the bit

10 )

notation.

of

the

EEPROM

(WE)

command.

I/O

line will be configured as an output.

I/O

lines to be outputs:

and therefore

will

is

A

vary

Command:
Response:

This command configures

Command: $iAlOoooool
Response:

Up to

64

110

lines may be configured at once,:

command: $iAIOFO1234AA5500FF88
Response:

The

'#

form

of

assignments (see ACK command).
The

A10

command stores the data direction assignments in EEPROM

I/O

lines are configured automatically when the device is powered up.

The

AIO

must

Clear Bit (CB)
Clear Position (CP)
Set Bit
Set Position (SP)
The Clear Bit command is used to turn
uses hexadecimal notation

(SB)

$IAIOFFFF

23

lines

to

be inputs and the LSB as an output:

*

the

AIO

command requires an 'ACK'

be preceded by a Write Enable

off

a single output bit. The

to

address the desired bit:

(WE)

to

complete

command.

the

direction

so

CB

command

that the

Command: $lCBOA
Response:

In this case the hexadecimal

affected

.

*

bit

number OA

is

turned off.

No

other bits are

If

the CB command is used with the

complete the command. For example:

1700

'#

prompt, an ACK command

Command

Set

is

required

4-3

to

Command: #1 CB1

F

Response: 'lCBlF57

In

this

case the module has echoed the command along with the response
checksum
response message is
module. Thus, the host may verify
Once the host is satisfied with the response data, it may activate the command by
responding with an Acknowledge

'57'.

At this point no output action

to

allow the host

(ACK)

has

taken place. The purpose

to

examine the command received by the

that

the command was received without error.

command:

of

the

command: $lACK
Response:

At this point the output bit (B1 F
The CB command will be executed only

assigned to be an
ERROR message
assigned with the

An attempt to clear a bit which does not exist
indicating an incorrect bit address.

To

verify the results

the Read Bit (RB) command.

The

Set

Bit

(SS)

addressed bit

*

in

this case) will be turned

if

output.

A!,

command operates exactly like

is

turned on.

An attempt

and

the command will be aborted. The bit direction may be

AO, and

of

a CB command the output bit value may be read back with

AIO

to

clear an input bit will result in an OUTPUT

commands.

off.

the addressed bit has been previously

will

result in a VALUE

the

CB

command except that the

ERROR,

The Clear Position
and

SB

commands except the desired bit is specified with a decimal address. The

folIowing two commands perform exactly the same function:

Command:
Response:

(CP)

and Set Position

$1

SBOF

*

(SP)

commands are similar

Command: $1SPf5

Response:

*

Clear Events (CE)

The Clear Events command clears the event counter

Command:

Response:

Note: When the events Counter reaches
command must be sent

also

See
command.

the Events Read & Clear

$1 CE

*

to

resume counting.

9999999,

(EC)

to

00000000,

it stops counting. A CE

to

the

or

CB

EC

4-10

1700

USERS

MANUAL

Continuous Input

The CIA command is used to specify the input address of a Continuous Input
module. The address is specified as a two-character code indicating the ASCII
equivalent

of

the address character:

Command:

Address

$1

CIA41

(CIA)

Response:

In this example,the input address is specified as ASCII '4l',which is the code for
character
strings containing address

The Continuous Input Address should not be confused with the polred address
as specified with the Setup

of

the CIA command.

the polled address will result in an ADDRESS ERROR response.
The Continuous Input Address

command must be preceded with a WE command. The address value may be
read back with the Read Input Address (RIA) Command.

*A'.

If

the module

An

is

set

to

Continuous Input mode, it will respond to data

'A.

(SU)

Command. Refer

attempt to set the CIA address with the same value of

is

stored in non-volatile memory. The

to

Chapter

6

for

specific

uses

CIA

Continuous Mode-Change (CMC)
Continuous

Mode

Disable

(CMD)

Continuous Mode-Edge (CMW
Continuous Mode-Input (CMI)

Continuous Mode-Timer (CMT)

The Continuous Mode Commands are used
Modes as described in Chapter

6.

Only one mode may be selected at any time.

to

select and enable Continuous

CMC

-

This output mode produces a data stream each time the input data lines

change.

CMD

-

Disable
modules are used in a polled system.

CME-

CMI

CMT-

All

Produce an output data stream when the edge-trigger input receives
positive transition.

-

Enable Continuous Input mode which will allow the module to accept

data from a continuous Output module.

This command enables the Timer Continuous Output Mode. In this

mode
Continuous Timer (CT) command.

five Continuous Mode commands require no argument and return no data:

Command:

all

Continuous Modes. This is the normal condition when

a

module will output data periodically at a rate specified by the

$1CMD

M1700

Response:

The Continuous Mode selection is saved in non-volatile memory arid is
immediately active when power is applied to the module. With the exception

the CMD command, all

and must be preceded with a
stored in non-volatile memory it is not write-protected in order to disable
continuous - output module quickly.

of

the Continuous Mode commands are write-protected

WE

command. Although the Disable command is

of

a

a

1700

The Continuous Mode setup may be read back with the Read Continuous Mode

(RCM) command.

Command

Set

4-1

1

Digital
The Digital input command is used to read the logical state
parallel. The

Input

Command:

Response:

The number of data bits read back
(see Setup chapter).

Command:
Response

The rightmost hex digit always represents the least-significant bits,

If

the

'#

version of the command is used,

digital data.

Digital Output (DO)

The Digital Output command is used

once:

Command: $1
Response:

In this example,
commands the least significant eight bits

off

turns
devices setup for

(DI)

D1

command reads the state

$1

DI

*1234

It

is possible

$1

DI

:

*

00

F

FOO

DOOOFF

i6

bits

of

the next eight bits

two

words of data.

of

all

of

of

both input and output lines.

is

a

function

to

read up

EE

OOC C 1234

do

to

specify the output data

output data are specified in parallel. The 'FF' data

(BOO

(808

to

BOF).

of

the unit's word length setup

to

64

channels:

not confuse the checksum with the

to

807)

to turn on. The

This

command is appropriate for

the

I/O

lines in

B00-B03.

to

all outputs at

'00'

data

The hex data length specified in the

setup in the

command example may be used with a device set up for eight words:

Command:

Response:
See the Setup chapter for word length description.
If

the

required
I/O

lines assigned

message

command.

Events

The

EC

automatically clears the count to zero:

Command:

Response: '0000123

M1700

DO

command

to

complete the output function (see

will

Read & Clear

command is used

or else the device will send a

$1

DO1 234567890ABCDEF

is

used with the

to

be inputs will ignore data sent by the

be generated by outputting data

(EC)

to

$1

EC

DO

command must match the word length

'#'

command prompt, an

ACK

to

read the value

SYNTAX

command).

input channels using

of

ERROR. The foIlowing

ACK

DO

command.

the Events Counter and

command

No

error

the

DO

is

4-12

The
and Clear Events

the

Counter

1700

EC

RE-CE

USERS

command eIiminafes a problem that may occur with a Read Events (RE)

sequence will be lost. The

is

read and cleared without missing any counts.

MANUAL

(CE)

command sequence. Any counts that may occur between

EC

command guarantees that the Event

Identification
The IDentification (ID) command allows the user
nonvolatile memory which may be read back at a later time with the Read

IDentification
no other affect on module operation. Any message up
be stored
data,

Message examples:

in

of

model number may be stored for later retrieval.

Command:

Response:
Command:

Response: *lIDBOILER
Command:

Response:
Command:

Response:

The

ID

command is write-protected.
Since the
be appended

Initial
The Initial Value command allows
digital
volatile memory
direction data previously specified with the assignment commands. Then it reads
out
the digital outputs are set to a known value upon startup.

ID

Value (IV)

outputs.

the Initial Value and performs an internal Digital Output command. Therefore

(ID)

to

write a message into the

(RID)

command.

memory. Useful information such as the module location, calibration

$I

IDBOILER

It

serves only as a convenience

to

ROOM

(module location)

to

the user and has

16

characters long may

*

#I

IDBOILER

$1ID

12/3/88

*

$lID

*

command has a variable length syntax, command checksums cannot

to

the message.

When the

to

set

3125

M1700

up the initial output conditions. First it reads the

ROOM

ROOM02

(calibration date)

(model number)

the

user to preset the startup condition of the

unit is powered up, it reads data from

(module location)

the

non-

I/O

The Initial Value is specified with hex data:

Command:
Response:

Read

The Read Assignment command is used
configuration of

notation, with a
assignment. The length of the hex data string will vary according to the number

110
section). The

Assignment

lines available and the number

LSB

Command:
Response:

This response indicates that the most significant eight
inputs and the least significant eight lines are configured as outputs.

$1

IVOOFF

*

(RA)

to

read back the data direction

all

the

I/O

lines. The assignments

'1'

signifying an output assignment and a

of

words setup in the device (see Setup

is always

$1

*OOFF

RA

to

the right:

are

represented in hexadecimal

'0'

indicating an input

I/O

lines are configured as

of

1700

Command

Set

4-1

3

For a device that is setup with a

the data direction of

Command: $1 RA

Response: 'OOFFOOFF88110044

Read Assignment Bit (RAB)
Read Assignment Position

The RAB and RAP commands are used
assignment of a single
addressing to identify
bit is assigned to be an input
output:

Command:

Response:

Command: $1 RAP1

Response:

Read
Read

The Read
input

Bit

(RB)

Position

Bit

or

output. The desired bit is specified

64

110

the

$lRABOE
'0

*I

(RP)

command is used to read the logical state of any individual

word

length of

lines:

(RAP)

110

line.. These commands use Bit or Position bit

desired bit. The M1700 will return an

,

or

an

'0

character

5

'8',

the RA command will read back

to

read back the input or output

'I'

character

if

the bit is assigned as an

with

the

Bit

notation:

I/O

if

the

line,

Command: $1 RBOF

Response:

The response data is a
positive logic.

Attempting
The Read Position command performs the same function except the data bit is

addressed in Position (decimal) notation:

Command: $1RP15

Response:

Note that the last two command examples perform the same function.

Read

The RCM command

Command: $1

Response:

The response is a single character indicating the Continuous Mode:

C-

D

E­!-

T- Continuous Output Timer

to

Continuous

Continuous Output Change Mode
Continuous Output Disabled
Continuous Output Edge Trigger
Continuous Input

*1

'1'

or

'0'

read a non-existing

'1

Mode

is

'0

used

RCM

(RCM)

to

read back the Continuous InpuVOutput Mode:

character indicating the state

I/O

line

will

result in a VALUE ERROR.

of

the

I/O

line in

4-14

Read Continuous Timer (RCT)
The RCT command is used
Timer (CT) command:

1700

USERS

MANUAL

to

read back the time value set by the Continuous

Command:

Response:
The Continuous Timer data is scaled in units of seconds.
The Continuous Timer function

Read
The RIA command reads back the Continuous Input Address stored in non­volatile memory. This command in useful only for modules that are
Continuous Input Mode (Chapter

The response to the RIA command is the
Address character. In this example,

Read Data (RD)
The Read Data (RD) command is used

MetraByte devices. Since the Keithley MetraByte Digital

acquire analog data, this command wi[l always result in a fixed response:

Input

Command:

Response:

Command:

Response:

$1

RCT

*+00005.00

Address (RIA)

$1

RIA

‘4

1

$1

RD

*+99999.99

is

detailed in Chapter

6).

ASCII

‘41’

is the ASCII code for character

to

6.

to

be used in

code

of

the Continuous Input

‘A.

read analog data from Keithley

110

products do not

Command:

Response:
The RD command is included in the

Keithley MetraByte products.

the host will acquire data with a software loop containing the

RD

command is included in digital
scanning

the digital

Watchdog Timer (see the
Since the

MetraByte system, a special truncated form
up scanning rates.
command is assumed by default:

Read

The

Events Counter. The output is a seven-digit decimal number:

loop.

I/O

RD

Command:

Response:

Event

RE

command reads the number

#I

RD

*1

RD+99999.99D9

1700

series to be compatible with other

In

many systems that include analog input modules,

I/O

products

A

proper response from an

device

command is the most frequently used command in a Keithley

is

powered up and running.

VvT

command).

If

a module

$1

is

addressed without a command, the

so

they may

RD

command is a good indication that

It

also serves to reset the

of

the command is available to speed

*+99999.99

Counter (RE)

of

events that have been accumulated in the

RD

command. The

be

included in the

RD

1700

Command

Set

4-1

5

Command: $1
Response: '00001

The maximum accumulated count is 9999999. When this count
Events counter stops counting. The counter may be cleared

ti

Events Read
The Event Count is cleared
The Remote Reset
When reading the Event Counter with a checksum, be sure not

checksum with the data.

Clear command

RE

07

(EC)

or the Clear Events command (CE).

to

zero upon power-up.

(RR)

does not affect the Event Count.

is

reached, the

at

any time with the

to

confuse the

Read Identification

The Read IDentification (RID) command reads out the user data stored by the
IDentification
convenience

(ID)

command. The

to

the user

ID

and

to

store information in the

RID

commands are included

M1700's

nonvolatiLe memory.

as

a

Command: $1 RID

Response:

*BOILER ROOM (exam p

I

e)

Command: #1 RID
Response: *lRIDBOILER

In this case the
previously stored by the ID command. See ID command.

RID

command has read back the message

ROOM54

(example)

"BOILER

ROOM"

Read Initial Value

The Read Initial Value command is

EEPROM.

power-up. The Initial Value is set with fhe Initial Value

The Initial Value

(RIV)

used

to

read back the Initial Value stored in

is

the output data used

Command: $1 RIV

Response:

The length
and the number

of

Read Input Bit

*OFOF

the hex data returned

of

words in the setup (see

(RIB)

is

dependant on the specific

Setup

chapter)

Read Input Position (RIP)

The Read Input commands are used

lines. The desired line

is

specified with either Bit or Position addressing:

to

read the logical state

Command: $lRIBOF
Response:

The module will respond with a '1'

line

in

positive logic.

Command:
Response:

Note that in the

'1

or a

'0'

$1 RIP15

'1

two

command examples the same

indicating the state

I/O

to

initialize the

(IV)

command.

M1700

of

individual

of

the specified

line is addressed.

M1700

model

the

upon

1/0

I/O

4-16

The

or

lines.

1700

RIB

an output. Therefore it is useful in monitoring the true state of output data

and

USERS

RIP

will read the state of any line whether

MANUAL

it

is configured

as

an input

Read

The Read Setup (RSU) command reads back the setup information loaded into
the module's nonvolatile memory with the Setup (SU) command. The response
to

characters.

The response contains the module's channel address, baud rate and other

parameters. Refer to the setup command

parameters in the setup information.

When reading the setup with
with the setup information.

The Read Setup

be compatible with the Keithley MetraByte

Setup

the

RSU

command is four bytes of information formatted as eight hex

Command:
Response:

Command:
Response:

Command:
Response:

Command:
Response:

(SU),

and Chapter 5 for a list

a

checksum, be sure not to confuse the checksum

$1

RSU

*31070102

#1

RSU

'1

RSU31070102E3

(RS)

command performs the same function, and is included to

MI

$1

RS

*31070102

#I

RS

'1

RS310701028E

000/2000

series.

of

Remote Reset

The Remote Reset
the module's microcomputer. This may be necessary

program is disrupted by static or other electrical disturbances.

Command:
Response:

Command:

Response:

The

RR

command

section).
The

RR

command will not affect the output data or the Event Counter.

The

RR

command is write-protected.

Read

The Read Watchdog Timer
activate the watchdog timer. The data is scaled in minutes.

Watchdog

(RR)

command allows the host

$1

RR

*

#1

RR

'1

RRFF

is

required

Timer

to

modify the baud rate

(RWT)

command reads the time interval necessary to

to

perform a program reset on

if

the module's internal

of

a

module (see Setup

1700

Command

Set 4-1

7

Command:

Response:

Command:

Response:

In each of the
watchdog timer period is
the Watchdog Timer

Setup Command (SU)

Each module contains an EEPROM (Electrically Erasable Programmable Read
Only Memory) which is used to store module setup information such as address,
baud rate, parity, etc. The EEPROM
information even
replace the usual array
equipment.

The Setup command is used to modify the user-specified parameters contained
in the EEPROM
command is
this manual has been devoted to its description. See Chapter

The

SU

four bytes

so

command requires an argument

of

setup information:

$1

RWT

*+00010.00
#1

RWT

*1

RWT+00010.0002

two

example commands, the response data indicates that the

10

minutes. The watchdog timer value may be set with

(WT)

command.

if

power is removed from the modu!e. The EEPROM is used to

of

DIP switches normally used

to

tailor the module

important to the proper operation of a module, a whole section of

(10

minutes)

(10

minutes)

is

a special type of memory that will retain

to

configure electronic

to

your

application. Since the Setup

5.

of

eight hexadecirnai digits to describe

Command:
Response:

Command:
Response:

Watchdog Timer (WT)

The Watchdog Timer
the time-out value

Command:
Response:

Command:
Response:

These two command examples set the watchdog time value

if

example,
minutes, the digital outputs will automatically
purpose
value in the event of a host

The Initial Value
The watchdog timer may be disabled by setting the timer value to

the module does not receive a valid command

of

the Watchdog Timer is to force the digital outputs

$1

SU31070102

*

#1

su31070102

*1SU3107010291

(WT)

command stores a data value in EEPROM specifying

of

the watchdog timer. The time data is scaled in minutes:

$1

WT+00010.00

#I

WT+00010.00

'1

WT+00010.00BO

to

10

for

be

forced to the Initial Value. The

to

or

communications link failure.

is

set with the

IV

command.

minutes. In this

a

period

a

known 'safe'

of

10

49999.99.

WT

command data less than

The

!AT

command is write protected.

.16

minutes will result in a VALUE ERROR.

4-18

1700

USERS

MANUAL

Write

The Write Enable
protected. This is to guard against accidentally writing over valuable data in the

EEPROM.

precede the write-protected command. The response
asterisk indicating that the module is ready
After the write-protected command is successfully completed, the module
becomes automatically write disabled. Each write-protected command must be
preceded individually with

Enable

To change any write protected parameter, the

Command:

(WE)

command must precede commands that are write-

WE

command must

to

the WE command is an

to

accept a write-protected command.

a

WE command. For example:

$1

WE

Response:

Command:

Response:

If

a module is
message other than
until

a

command is successfully completed resulting in an
the user to correct the command error without having to execute another
command.

ERROR

All

modules feature extensive error checking
erroneous operation. Any errors detected will result in an error message and the
command will be aborted.

MESSAGES

#1

WE

'1

WEF7

write

enabled and the execution

WRITE

PROTECTED, the module will remain write enabled

of

a command results

' + '

prompt. This allows

on

input commands

in

an error

to

WE

avoid

All error messages begin with
error description. The error messages have the same format for either the

#

'

prompts. For example:

?I

SYNTAX

There are eight error messages, and each error message begins with a different
character.
not necessary to read the whole string.

ADDRESS ERROR

There are four

($OO),

attempt is made
command. An attempt
error.

An attempt to use the Continuous Input Address (CIA) command to specify an
illegal address or an address identical

BAD

This error
The module recognizes any two hex characters appended to a command string
as a checksum. Usually a BAD CHECKSUM error is due
on the communications line. Often, repeating the command solves the problem.

If

the error persists, either the checksum is calculated incorrectly or there

Host

CR

($OD),

CHECKSUM

is

ERROR

computer software can identify an error by the first character; it

ASCII

values that are illegal for use as a module address: NULL

$

($24),

to

load an illegal address into a module with the Setup (SU)

to

caused by an incorrect checksum included in the command string.

'I?'',

followed by the channel address, a space and

and

#

($23).

The ADDRESS

load an address greater than

to

the polling address will create an error.

ERROR

will occur when an

$7F

will also produce an

to

noise

or

' $ '

or

is

interference

is

a

'

1700

problem with the communications channel. More reliable transmissions might be
obtained by using a lower baud rate.

Command

Set

4-1

9

COMMAND

This error occurs when a command is not recognized by the module. Often this
error results when the command is sent with lower-case letters. All valid
commands are upper-case.

OUTPUT ERROR

An attempt
that has been assigned as an input will generate an OUTPUT
The Digital Output

PARITY E R

A

parity error can only occur

Usually a parity error results from a bit error caused by interference on the

communications line. Random parity errors are usually overcome by simply

repeating the command.
may have

A

consistent parity error will result
parity. In this situation, the easiest solution may be to change the parity in the host
to obtain communication.
the desired value with

The parity may be changed or turned

SYNTAX

A

SYNTAX
caused by having
or in the wrong place. Table

ERROR

to

use a

CB,

(DO)

command will

RO

R

to

be improved

the

ERROR

ERROR will result

too

few or

CP,

SB,

or

SP

command

to

set or clear a digital

I/O

ERROR.

not

generate an OUTPUT

if

the module is setup with parity on (see Setup).

If

too many errors occur, the communications channel

or

a slower baud rate may be used.

if

the host parity does not match the module

At

this point the parity in

Setup

(SU)

command.

off

by using Default Mode.

if

the structure

too

many characters, signs

4.1

lists the correct

of

the

syntax

the

module may be changed to

command

or

for

ERROR.

is

not correct. This

decimal points missing

all the commands.

line

is

VALUE ERROR

This error results when an incorrect character is used as a numerical value. Data
values can only contain decimal digits

WRITE

All commands that write data into nonvolatile memory are write-protected
prevent accidental erasures. These commands must be preceded with a Write

Enable

PROTECTED

(WE)

command or else a WRITE PROTECTED error will result.

0-9.

Hex values can range from

0-F.

to

Chapter

5

Setup InformatiodSetUp Command

The Keithley MetraByle modules feature a wide choice of user configurable
options which gives them the flexibility to operate on virtually any computer
terminai based system. The user options include a choice of baud rate, parity,
address, and many other parameters. The particular choice of options for a
module is referred

The setup information is loaded into the module using the Setup (SU) command.
The SU command stores
memory contained in the module. Once the information
be powered down indefinitely
The nonvolatile memory is implemented with EEPROM
to replace.

The

EEPROM
for option selection. The module never has
options are selected through the communications
be changed at any time even though the module may be Iocated thousands of
feet away from the host computer
module may be read back at any time using the Read Setup command

The following options can be specified by the Setup command:

to

as the setup information.

4

bytes (32 bits)

(10

years minimum) without losing the setup data.

has many advantages over DIP switches or jumpers normally used

of

of

setup information into a nonvolatile

to

be opened because all of the

terminal. The

is

stored, the module can

so

there are no batteries

port.

This allows the setup

setup

information stored in a

(RSU).

or

to

Channel address (124 values)
Li nefeeds
Parity
Baud rate

(odd,

even, none)

(300

to

38,400)

Echo
Communication

Word

Each

on

length

of

these options will be described in detail below. For a quick look-up chart

all options, refer to Tables

Command

The general format

$lSU[bytel][byte ZJ[byte 3][byte

A

typical Setup command would took like: $lSU31070102

Notice that each byte is represented by
example, byte
of binary
exactly
SYNTAX ERROR.

For the purposes
order bit of a byte

8

0011

hex

delay

(0-6

characters)

5.1-4.

Syntax

for

the Setup

1

is described by the ASCII characters

0001

(31 hex). The operand of a

(0-F)

characters. Any deviation from this format will result in a

of

describing the Setup command, 'bit

of

data.

'Bit

0'

refers

(SU)

command is:

to

41

its

two-character

lowest-order bit

SU

ASCII

equivalent. In this

'31'

which is the equivalent

command must contain

7'

refers to the highest-

'bit number':
binary data:

7

654321

0

0

1

1

0 0 0

0

1

=$31 (hex)

5-2

1700

The

SU

setup data; therefore each

(WE)

command. To abort an

character (an

USERS

command is write protected

'x'

for example)

MANUAL

to

guard against erroneous changes in the

SU

command must be preceded by a Write Enable

SU

command in progress, simply send a non-hex

to

generate a SYNTAX

ERROR,

and

try

again.

Caution: Care must be exercised in using the

result in changing communications parameters (address, baud rate, panty) which

will

result in a loss
cases the user may have to resort to using Default Mode to restore the proper
setups. The recommended procedure is
command
command.

Byte

Byte 1 contains the module (channel) address. The address is stored
ASCII code for the string character used
command

'1'.

If

the address

module address

ASCII

$181132070102.

from
The module will no longer respond to address
When using the

record the new address in a place that is easily retrievable. The only way to
communicate with a module with an unknown address is with the Default Mode.

The
four ASCII codes that are illegal

$24,

these codes
will remain unchanged. This leaves a total of

loaded with the
printable characters be used
debugging with a dumb terminal. Refer to Appendix A for a list of ASCII codes.
Table

to

1

$lSU31070102

our

sample command is sent

code for the character

'l'to

'2'.

most

significant bit of byte 1 (bit

$23

which are

5.1

lists the printable ASCII codes that may be used as addresses.

of

communications between the host and the module. In some

to examine the existing setup data before proceeding with the SU

,

the first byte

to

a

module, the EEPROM will be loaded with

'l',

which in this panicular case remains unchanged.

to

'2'

,

byte 1 of the Setup command becomes

'2'.

Now the command will

When this command is sent, the module address is changed

SU

for

an address

SU

command.

command

ASCII

to

change the address

7)

for

use

as an address. These codes are

codes

will

for

the characters

cause an ADDRESS

It

is highly recommended that only ASCII codes

($21

to

SU

command. Improper use may

to

first use the Read Setup (RS)

to

address the module. In

'31'

is the ASCII code

for

To

'32',

look

'1'.

of

a module, be sure to

must

be

set

to

'0.

In addition, there are

NUL,

CR,

$,

ERROR

124

possible addresses that can be

$7E)

which greatly simplifies system

and the setup data

as

the

our

example

the character

change the

which

is

the

like this:

$00,

$OD,

and

#.

Using

for

Setup

Information/SetUp

Command

5-3

Table

HEX

21

22
25
26

27
28

29

2A
28
2c

20

2E

2F

30

31

32

33
34
35
36

37

38

39

Byte

Byte 2 is used to configure some
channel; linefeeds, parity, and baud rate.

5.1 Byte 1 ASCII Printable Characters.
ASCII

I

H

%

&

(

1

+

3

I

0

1

2

3

4

5

6

7
8
9

2

HEX

3A

38

3c

3D

3E

3F
40
41
42
43
44
45
46
47
48
49

4A

4B

4c
4D
4E
4F

50

ASCII

1

c

- -

5

7

@

A

B

C

0

E

F

G

H

I

J

K

L

u

N

0

P

HEX

51

52

53
54

55
56
57

58

59

5A

5B

5c

5D

5E

5F

60

61
62
63
64
65
66
67

of

the characteristics of the communications

ASCII

Q

R

S

T

u

V
W
X

Y

z

I

\

1

n

-

a

b

C

d

e

f

g

HEX

68
69
6A
6B
6C
60
6E

6F

70

71
72
73

74

75
76
77
78
79
7A
78
7c
7D
7E

ASCII

h

i

i

k

I

m

n

0

P

q

r

S

t

U

Y

W

X

Y

z

I

I

1

-

L

i

nef

eeds

The most significant bit
module. This option can be useful when using the module with a dumb terminal.
All responses from the modules are terminated with

Most

terminals will generate a automatic linefeed when a carriage return is
detected. However,
generate the linefeed
linefeed (ASCII
linefeeds are transmitted.

When using the

the checksum calculation.

Parity

Bits 5 and 6 select the parity to be used by the module. Bit 5 turns the parity on

off.

and
of characters transmitted by the module

If

bit 5 is

output by €he module

If

bit 6 is

If

a parity error is detected by

message. This is usually caused by noise on the communications line.

If

'j',

'O',

$OA)

'#

bit

5

is

'O',

the parity

panty

is

of

byte 2 (bit

for

terminals that

if

desired. By setting bit 7 to

before and after each response.

command prompt, the linefeed characters are not included in

the parity

of

command strings is checked and the parity of characters

is

calculated as specified by bit

even:

if

of

the command string is ignored and the parity bit

bit

6

is

the

module, it will respond with

7)

controls linefeed generation by the

a

carnage return (ASCII

do

not have this capability, the modules can

'1'

the module will send a

If

bit 7 is cleared

is

set

to

'0'.

6.

'i',

parity

is

odd.

a

PARITY

$OD).

(0),

no

ERROR

5-4

1700

If

parity setup values are changed with the
command
becomes effective immediately after the response message from the
command.

USERS

will

be transmitted with the old parity setup. The new parity setup

MANUAL

SU

command, the response to the

SU

SU

Baud

Bits
from eight values between
desired code.

The baud rate selection

after an

reset must occur.
command or powering down. This extra level

ensure that communications to the module
important when changing the baud rate of an

information on changing baud rate, refer to Chapter

Let's run through an exampIe of changing the baud rate. Assume

module contains the setup data value
the

no parity, and baud rate

module we would get:

Rate

0-2

specify the communications baud rate. The baud rate can be selected

300

and

38400

is

the only setup data that

SU

command. In order for the baud rate

A

reset is performed by sending a Remote Reset

of

SU

command chart we can determine that the module

300.

If

we perform the Read Setup command with this

Command: $1

RS

baud. Refer to Table

is

to

be actually changed, a module

of

write protection is necessary

is

not accidently

RS-232C

3.

'31 0701

02'.

Byte 2 is '07'. By referring to

not implemented directly

lost.

string. For more

is

set

for no linefeeds,

Response: *31070102

Let's say we wish

is

'OjO'

(from Table

command we must first send a Write Enable command because

protected:

to

change the baud

5.2).

This would change byte 2 to

rate

to

9600

baud. The code for

'02'.

To perform the

5.2

for the

(RR)

to

This is very

our

sample

9600

baud

SU

SU

is write

Command: $1

Response:

WE

*

Command: $1 SU31020180

Response:

This sequence of messages

baud rate

We can use the Read Setup

of

the module. The module remains in

Command:

$1

RS

is

done in

(RS)

300

command

baud because that

300

to

check the setup data:

Response: *31020102

Notice that although the module is communicating in

indicates a baud rate of

9600,

send a Remote Reset

Command:

Response:

Command:

Response:

Up

to

this point all communications have been sent at

not

respond

running at

9600

baud to continue operation.

to

any further communications at

9600

baud. At this point the host computer or terminal must be set

$1

*

$1

*

9600

WE

RR

(byte

(RR)

2

=

'02').

command

To actually change the baud rate

(RR

is write protected):

300

was

the original

baud after this sequence.

300

baud, the setup data

300

baud. The module will

baud because it is now

to

to

Setup Inforrnation/SetUp Command

If

the module does not respond
incorrect. Try various baud rates from the host until the module responds. The
last resort is to set the module to Default Mode where the baud rate is always

Setting a string of RS-232C modules to a new baud rate requires special
consideration. Refer

Bits

3

and

4

These two bits of byte 2 are not used and should be set

to

Chapter 3 for instructions.

to

the new baud rate,

most

likely the setup data is

to

'0,

5-5

300.

Table
BYTE
FUNCTION DATA BIT

LINEFEED
NO LINEFEED
NO PARITY
NO PARITY

EVEN

ODD PARITY
NOT USED
38400 BAUD

19200

9600

4800 BAUD

2400

1200
600

300 BAUD

Byte

This byte contains the setup information for additional communications options.
The default value for this byte is

Echo

When bit 2 is set
the communications line. This option
232C modules. Echo is optional for systems with a single
must be cleared
description.

5.2

2

PARITY

BAUD

BAUD
BAUD

BAUD

BAUD

3

Byte

2:

Linefeed, Parity

7654

and

Baud Rate.

3210

1

0

00

10
01

11

xx

000

001
010

011

100
101
I10

111

'01'.

to

'l',

the module will retransmit any characters it has received on

is

necessary to 'daisy-chain' multiple

to

'0'

on

RS-485

RS-232C

models. See Chapter 3 for a more complete

module. Bit

RS-

2

Delay

Bits 0 and I specify a minimum turn-around delay between a command and the
module response. This delay time
enough
particularly true for systems that use software
added
section of Chapter
amount of time required to transmit one character with the baud rate specified in
byte
the delay is
shown

In some systems, such as
a linefeed
terminated by a CR and will ignore the linefeed.
collision between the linefeed and the module response, the module should be
setup

to

capture data from quick-responding commands such as

to

the typical command delays listed in the Software Considerations

3.

Each unit

2.

For

example, one unit of delay at

0.26

mS. The number of delay units is selectable from

in

Table

5.3.

IBM

(LF).

The modules

to

delay by 2 units.

is

useful

on

host systems that are not

RD.

UART's.

of

delay specified by bits 0 and 1 is equal to the

300

baud is 33.3 mS; for

BASIC,

a carriage return

will

respond immediately after a command

The specified delay is

38.4

(CR)

is always followed by

To

avoid a communications

fast

This

kilobaud

0

to

6

is

as

5-6

1700

USERS

MANUAL

Table

BYTE

FUNCTION

NOT

NO

ECHO

NO

2

4

6

Byte

Event Counter
The M1711M712 contains a programmable digital filter
of the Event Counter. The filter is particularly useful when the Event Counter is
used to count transitions from switches or other electro-mechanical contacts. The

filter will debounce noisy signals to provide error-free transition counting.

The filter constant is controIled by bits
shown in Table
This setting is ideal

noisy signals, filter constants of
the digital filter is described in Chapter 2.

Word

The M1700 command set is used by many Keithley MetraByte digital
devices, ranging from

DI,

setup is used to adjust the amount of

Mi700 device. One word of data

hexadecimal digits. The number

most appropriate for a specific device.

5.3

3

USED

ECHO

DELAYS

BYTE
BYTE
BYTE

4

Length

and

RA

Byte 3 Options.

DATA BIT

7654 3210

xxxx

x

0

1

00

TIME

TIME
TIME

DELAYS
DELAYS
DELAYS

Filter

4

and 5 of byte

5.4.

If

no fitter is selected, the Event Counter bandwidth is 20kHz.

for

electronic signals with clean transitions.

5,

20, and 50ms are available. The operation

1

to

64

I/O

lines. Many

commands operate on all of the data lines in paralIel. The word length

is

defined to be eight bits, represented by two

of

words required

of

the commands such as the

hex

bit data transmitted to and from

may

01

10

11

to

control the bandwidth

4.

The selections are

To

debounce

be adjusted to a value

of

I/O

DO,

the

1

The word length can vary from

of

0

is not allowed.

As

an example, a

would be: 31070102
The

'02'

indicates that the device

typical

Since the
the data length is incorrect, an error will be generaied:

The word length setup

DO

command to this unit would be:

Command:
Response:

Mi712

Command:
Response:

Command:
Response: *ABCD

Mi712

$1

DO1234

*

is setup for

$1

DO12345

?1

SYNTAX

also

$ID1

to 8 words, specified by bits

has

15

I/O

lines, and a typical setup for this device

is

setup for two words, or

two

words,

affects the parallel readback commands such as:

if

will accept the four digits of hex data.

ERROR

0-2.

A

16

bits

word length

of

data.

A

If

Setup

Information/SetUp Command

5-7

Notice that with a word setup
same effect occurs with the

It

is possible

the physical 110 data width. For example, the M1712 may be setup with word

length
With this setup, the

Command:

Response:

The correct

to

setup a module with a word length that does not correspond with

=

'1'. Setup data

DO

argument is now

DI

command returns eight bits of data:

$1

'CD

=

DI

31

of

RA

0701

'2,

and

01

two

the

DI

command returns 2 words

RIV

commands.

hex digits:

of

data. The

Command: $1 DO34

Response:

A

word length of

device are used or
Regardless of the word setup, the rightmost hex digit

least significant 110 data. The most significant data is appended or truncated as
necessary corresponding to the word length setup.

It

is

also possible for the word length

the device. The M1712 may be setup with a word length of

*

'1'

may be appropriate for the

if

maximum communications speed is desired.

to

be greater than the physical data width

MI712

if

of

the bit data is always the

only

eight bits of the

'3':

3

10701

of

03

In this

case,

all

parallel data values must be 24 bits or

Command:

Response:

Command:

$1

DO123456

*

$1

DI

six

hex digits wide:

Response: *003456

The M1712 contains
of the

24

bits

will

most significant bits.
The deliberate use

streamlining host software. For example, in
devices, the host software may be simplified by standardizing

for alt devices.

The word length setup has
'Position' addressing.

15

110

lines. For the

be ignored. The

of

dummy data may seem wasteful, but it can be useful for

DI

no

affect on commands using single-bit 'Bit' or

DO

command, the most significant nine

command will return with

a

system with a mix

'0'

data for the nine

of

24 and

to

word length

15

bit

'3'

5-8

1700

USERS

MANUAL

BYTE

FUN CTlON
NOT USED

NO FILTER

5ms

20ms

50ms

1

2

3

4

5

6

7

8

Setup

Until you become completely familiar with the Setup command, the best method
of changing setups is
change has been made correctly. Attempting
often lead
is
parameter at a time. Use the Read Setup
information currently in the module as a basis for creating a new setup.
example:

4

DATA BIT

7654

xx

00

01

10
11

WORD

WORDS

WORDS

WORDS

WORDS
WORDS

WORDS

WORDS

Hints

to

change one parameter at a time and

to

confusion.

to

reload the factory setup as shown in Table

If

you reach a state

3210

0001

0010
0011
0100
0101
0110
0111

1000

to

verify that the

to

modify all the setups

of

total confusion, the best recourse

5.5

and

try

again, changing one

(RS)

command

to

examine the setup

at

once can

For

Assume you have a
may be used in a daisy-chain (See Communications). Read out the current setup

with the Read Setup command:

Command:
Response:

By referring to Table

From the

hexadecimal representation of binary

to

'1'.

05.

changing only byte

RS

command we see that byte 3 is currently set

This results in binary

To perform the

Command:

Response:
Command:

Mi711

$1

*31070102

5.3,

SU

3:

$1

unit and you wish to set the unit

RS

we find that the echo is controlled by bit

0000

0000

command, use the data read out with the

WE

0101.

(SU

is

0001.

To

set

The new hexadecimal value

write-protected)

*

$lSU31070502

to

echo

so

that

2

of

byte

to

01.

This is the

echo, bit 2 must be

of

byte 3 is

RS

command,

3.

set

Response:

Verify that the module is echoing characters and the setup is correct.
By using the

problems associated with incorrect setups may be identified immediately. Once a
satisfactory setup has been developed, record the setup value and use it
configure similar modules.

If

you commit an error in using the Setup command,

communications with the module. In this case, it may be necessary to use the

DefauR Mode

RS

command and changing one setup parameter

to

re-establish communications.

at

it

is possibie

a

time, any

to

to

lose

it

Setup Information/SetUp Command

5-9

Table

(All

Model Setup Message
MI711
M1712 31 0701
M1750 31 0701 03
M1770 31 0701

SlOaO

Setting up your
program provided in the 51000 software package. The

IBM
menu-driven operator interface which greatly simplifies the setup process and

decreases the chances

5.5

Factory

modules from the factory are set for address

31

Setups

0701

02
02

08

by

Model.

Software

MlOOO

Pc's

or compatibles and is free

module may be greatly simplified by using the setup

of

charge. The setup program provides a

of

setup errors.

'l',

300

baud, no panty)

SIOOO

software runs

on

Chapter

5

Continuous Inputloutput

The

M1711/1712

communicate without being polled by a host computer. Collectively these modes
are called Continuous InpuVOutput Modes.
the host may be greatly simplified and in
altogether.

Continuous Output

A

M1711/1712

format as the response to a

‘1

D18000BO

modules may be setup in special modes which ailow them to

In

many appIications the burden on

some

cases the host may be eliminated

in continuous mode will produce an output string in the same

#1

DI

command:

Note that the output message contains the response prompt
address
continuous mode, a
command without actually receiving the command. The output data string may
triggered in one

Timer Mode:
Continuous Timer (CT) command. The CT command specifies a time period that
repeats indefinitely. After each timeout, the module will output the status data.
The module will periodically output the digital input data until the continuous
mode is disabled.

Edge-Trigger
it receives
produce an output in response
daisy-chaining several continuous output modules together.

Change Mode: In this mode the
the

Continuous Input

A

continuous-output module. The data string from a continuous output module is
interpreted as an output command by a continuous input module. This allows
data
without

(l),

the status of the digital

M1711/1712

of

three ways:

In

this mode, a software timer is activated in the module with the

Mode:

a

trigger signal

I/O

lines.

If

module setup for continuous input

to

be read

a

host computer.

In this mode the

on

the BOOlEV

a change is detected in status, an output data message is initiated.

at

one

module and replicated

110

module produces a response to a

M1711/1712

to

an external event.

M171111712

lines

(8000)

110

Pin. The edge trigger mode will

continuously monitors the status

will

respond

at

and a checksum

will output a data string when

It

also

to

the outputs of another module

(‘1,

the module

(BO).

In

#1Dl

be

provides a means

of

of

data produced by a

Continuous Input/Output Commands

The

MI

71 1

/I

71 2

modules contain several commands

modes. They are listed here for quick reference.
each command may be found in the Chapter

$ICMD

$1

CMT

$1

CME

$1

CMC

$1

CMI

Continuous Mode Disable
Enable Timer-Triggered Continuous
Enable Edge-Triggered Continuous Output Mode
Enable Change-Triggered Continuous Output Mode
Enable Continuous Input Mode

4.

to

setup the continuous

A

more complete description

Output

Mode

of

6-2

1700

$1

$1

$1

$1CIA Specify Continuous Address

$1

Continuous Output Trigger Signal

In order to facilitate daisy-chaining of continuous output modules, each module
will produce an output trigger signal each time it completes an output data string.
The output trigger is
The Default
communications setup. This
Mode. However, when
momentarily becomes an output and produces a low-going trigger pulse. This
trigger pulse may be used to trigger another module set in Edge trigger mode. In
this manner, many modules may be daisy-chained together in continuous mode.

Applications
There is a wide variety
the continuous mode modules.
connection. However, a variety
usage.

USERS

RCM

CT Specify Continuous Timer value in seconds.
RCT Read Continuous Timer

RIA Read Continuous Input Address

pin is normally an input pin used

MANUAL

Read Continuous Mode Type.
Response is D, T,
Change

a

or

5

millisecond low pulse which appears

is

a

module produces a continuous output, the Default * pin

of

system configurations which may be implemented with

E, C or I for Disabled, Timer, Edge,

Input respectively.

on

to

place the module in a known

aIso true when a module is set for Continuous

It

would be impossible to detail every possible

of

examples will be given to demonstrate typical

the Default pin.

A)

Timer Mode (Figure

In

this configuration,
computer
obtain data. The host computer must have
proper operation.

For this example, we will setup the
commands are

I)

Setup the

communications

or

display device.

Command:

Response:

a

not

shown but necessary for write-protected commands).

Mi712

to

the host.

$1

1)

M1712

SU31070102

module is set to continuously output data to a host

It

is

not necessary for the host to poll the

MI712

as usual with the setup

to output data every

M1712

an

interrupt-driven serial input for

10

seconds.

(SU)

command for correct

to

(WE

Continuous

Input/Output

6-3

2) Assign the

Command: $1

I/O

lines

of

AIOOOOO

the M1712 to be inputs:

Response:

3)

Set the Continuous Timer

(CT)

for

a 10 second interval:

Command: $1 CT+00010.00
Response:

This

tells

the

MI712

4)

Activate the continuous output with the Continuous Mode Timer

command. This will activate the continuous output data.

5)

Every

I0

seconds, the M1712 will read the status

status of those lines as

Response:

6)

The Continuous Mode may be disabled by the host by sending a Continuous

Mode Disable command:

to output data continuously in

if

it

was responding to

*ID1123482

a

#I

DI

10

second intervals

of

its

I/O

lines and output the

Command:

Command: $1 CMD
Response:

The CMD is not write-protected and a Write Enable

required.

*

(WE)

command is not

(CMT)

To

avoid communications collisions, the host

response, and then immediately issue the CMD command. In

example, the host has 10 seconds to issue the

of

a collision is remote.

even

if

the Continuous Timer
command immediately after the carriage return from the M1712
When the M1712 reads
temporarily halt the continuous mode output and look for an address character.
the MI712 detects its own address, it will
command. Otherwise it will resume the continuous mode output.

B)

Timer Mode With

This configuration is shown in Figure
with digital outputs.
outputs:

It

is

possible for the host

is

set for 0 seconds.

a

'$'or

'#'

character on the communications line, it will

Outputs

1.

For

example, the high-order 7 bits could be configured

should

read

However, this time the

wait

for

a continuous output

CMD

command,

to

disable the continuous mode

The

host

must issue the CMD

and process the rest of the

our

current

so

the likelihood

is

received.

M1712

is

setup

Command: $lAIOFFOO
Response:

Setup the Continuous Mode just like example

Command:

$ICT

+OOOiO.OO

A:

Response:
Command: $1CMT

Response:

*

If

as

The M1712 will continuously output the status
outputs, every 10 seconds.

of

the

I/O

lines, including the

6-4

1700

USERS

MANUAL

However, with this setup, the host may respond with
commands
other control decision.

It

is

not necessary to disable the continuous mode before issuing the output

command. However,

should be timed

way to

immediately issue the output command.
Another method

Mode
acts normally and any
Mode may be resumed with a Continuous Mode Timer (CMT) command.

C)

Edge-Trigger
The M1712 may be triggered by an external digital signal which will command the
M1712

to

control the digitaI outputs in response to the input data or some

to

avoid communications collisions the

to

avoid the continuous response from the

do

fhis is to wait for a continuous output string from

of

performing output functions is to disable the Continuous

by

issuing a Continuous Mode Disable

of

the

I/O

commands may be performed. The Continuous

to

read the status

Mode

of

With
the

I/O

Host

lines and report the data (Figure

(CMD)

DO,

SB,

CB,

or other output

host

M1712.

the

module and then

command. The

command

The easiest

M1712

2).

now

The external trigger signal

BOO

the

application. The trigger input

will withstand a

switch by adding a pull-up resistor. (Figure

pin is used

for

0-30V

is

connected

the trigger, it

input without damage. The input may be triggered with a

is

designed

is

not available for general-purpose

to

the

SOO/EV

pin

of

the module. Since

I/O

to

accept a TTL-level signal, although

3)

in this

it

300lEY

Continuous

InpuVOutput

6-5

The module

the MI

1)

Use

In this case the M1712 will be setup

Command:

Response:

2)

The

Other
application:

Command

Response:

This command assigns BOO through
outputs.

is

triggered on a positive-going edge to the

71

2

for edge-trigger mode:

the setup

(SU)

command to set the desired communications parameters.

for

$1

SU32070102

*

BOO

I/O

line must be assigned as an input to accept the trigger signal.

I/O

lines may be assigned as inputs

:

$2

A

I0

F

FOO

t

lYOK

B

BOOlEV

address

B07

'2':

or

outputs depending on the

as inputs, and

B08

through

pin.To setup

BOE

as

3)

The Continuous Timer (CT) command may be used
between the Trigger signal and the output data string. This feature is

some applications when multiple modules are tied together which will
illustrated in other examples. For this and most edge-trigger applications, set the
Continuous timer to

Command:
Response:

4)

Enable the edge trigger mode with the Continuous Mode Edge-trigger

command.

5)

When the M1712 senses a positive-going trigger on the BOOlEV line, it
perform the equivalent

Response:

6)

The host may terminate the edge-trigger mode with a Continuous Mode
Disable
collisions between the host command and responses from the module. The best

(CMD)

0

seconds:

$2CT+00000.00

of

a

#2DI

command and output the data:

*2DI123583

command. Precautions must be used

to

specify a delay time

useful

to

avoid communications

in

be

(CME)

wilt

6-6

1700

USERS

MANUAL

method of disabling the continuous mode
CMD command:

Command:

Response: '2CMD30

The command is issued by the host and then the host looks for the correct
response string to be returned
detected, then the host knows that the continuous mode has been disabled.
the correct response string
command collided with response data from the module. The host simply repeats
the CMD command until the correct response
collisions are not harmful to
be able to accept framing errors and 'noise' characters gracefully when collisions
occur.

D) Continuous Output Daisy-Chain With

#2CMD

by

is

not received, it may be assumed that the CMD

RS485

is

to issue the 'long form' version of the

the

M1712. If

hardware. However, the host serial input must

the correct response string

is

obtained. Communications

Host

(Figure

4)

is

If

ADDRESS

EDGE

This configuration uses one module (address
trigger signal on the Default

set

for

Edge trigger mode. The third module (address

mode and receives its trigger signal from the Default
Additional edge-triggered modules may be implemented by connecting the
trigger output (Default

module in the series, and this connection may be repeated for any additional

modules.

123)

The net result
without the need for polling by the host. The data stream from this system would
typically

A

typical application will have 1 timer module with any number

of edge-triggered modules.

of

this connection

look

like this:

*)

of

*

line to trigger another module (address

a module

#3

is

a periodic burst of data from all the modules

1)

to the trigger input

#3

MODE

in Timer mode which produces a

3)

is

set-up

(BOO/EV)

ADDRESS

EDGE

MODE

for

edge-trigger

pin

of

module

#2

2)

which is

of

the next

(up

#2.

to

ADDRESS

TIER

MODE

#I

Continuous

'1

Dl123482
*2D10001AA
'3DIFFFF02

Each data string is terminated by a carriage return. Note that the module address

to

is transmitted with the data
The easiest way of setting up a system like this is to install the modules and

operate them as a polled system first. Once the wiring and the operation
modules is established, the string may
all the Edge Triggered modules as described
setup the Timer module
Timer module must be long enough
time is too short, module
finished, resulting in a communications collision.

In

some cases, especially
the amount of data transmitted may overload the serial
this case, the data may be slowed down by specifying a finite amount of time in

the

Continuous Timer
trigger mode will delay the output data after
in CT.

The

host

may disable the continuous output data by sending a Continuous Mode

Disable command

to

the timer module:

easily determine the origin

be

set for Continuous Mode. First, set

in

Example

as

described in Example

to

allow all the modules to respond.

#I

will start

if

a large number of modules are connected in a string,

(CT)

of each edge-triggered module. A module in Edge

to

A.

The CT time specified in the

output data before module

it

is triggered by the amount specified

Input/Output 6-7

of

the data.

C.

The last step

port

buffer of the

of

all

is

If

the CT

#3

host.

the

up

to

has

In

Command:

Response:

The host should repeat the
timer mode is disabled, the string of modules may be polled by the host.
to continuous output operation, enable the continuous
module:

Command:

Response:

E)

Change Mode (Figure

A

MI712

digital input lines has changed state. The module
reporting the new state

module set up for change mode will output a data string

HOST

#1

CMD

*fCMD2F

CMD

$1

CMT

*

5)

GND

of

the inputs.

until the proper response is obtained. After the

I

-

-

DATA
DATA'

GND

mode

will

output the data string

of the Timer

if

To

one

return

of

its

To setup the
Assign the desired

M1712

for change mode:

I/O

lines to inputs:

6-8

1700

USERS

MANUAL

Command:

$1

AIOOOFF

Response:

Note that not all lines are required to be inputs. In this example, digitaI
BOO-BO7

For

Set

The
state.

After the response
The host may disable the continuous output mode by sending

are set

this example, set the Continuous Timer

Command:

Response:

the module

Command:

Response:

M1712

If a change

*I

DlOl

Command:

Response:

to

outputs and

$1

CT+OOOOO.OO

608-BOE

are set

*

to

Continuous Mode:

$1

CMC

*

will continually scan the Digital

is

found, the new state of the I/O lines is reported

FFDS

is

transmitted, the

#I

CMD

*1CMD2F

M1712

to

inputs.

to

zero:

110

lines

to

detect any changes of

will resume scanning the

a

CMD command:

to

the host:

110

I/O

lines.

lines

The module may now be interrogated with the normal command -response
sequence. This method is useful when the host is required

to

response
lines (in this case 600-607) with normal
is completed, the
command.

The change mode is ideal in applications where the state
expected
alarm switches,
host computer. By using a
change in input status on
scanning inputs that are static.

a change in the input status. The host may control the digital output

I10

commands. After the control function

M1712

to

change infrequently. Inputs such as security switches, fire detectors,

etc.

may be returned

are not expected

Mi712

in change mode, the host may be alerted to a

an

interrupt basis thereby saving computer time

to

Continuous Mode with the CMC

to

change but must be detected by the

to

produce an output

of

the digital inputs is

F)

Change

Mode

With Multiple

Continuous

Modules: (Figure

Input/Output

6)

6-9

It is possible to configure
mode on the same serial

This configuration may be used

one drawback to this connection is that there is no means of avoiding a
communications collision
exactly the same time. This
considerations aside, this type
guidelines are adhered

1)

The inputs being scanned are primarily static. This is usually the case when

monitoring security and alarm type
indicates an extraordinary event. This

would

occur

at the same time.

2)

Checksums and parity must be used

by data collisions.

3)

The host input
evidence that a change in input status has occurred. This wilI cover the unlikely
possibility that

the

host

may disable the Continuous Mode and poll the modules directly to read

the input lines.

4)

Use the highest baud rate possible to reduce the likelihood of collisions.

5)

The Continuous Timer may be used
particularly useful

causing a continuous stream of data from one module. The CT command may be
used to set a 'dead time' after

port

two

modules are responding at exactly the same time. In this case

if

two

or mode modules

fo

port.

to

extend the number of inputs monitored. The

if

two modules attempt to output data messages at

will

result in communications errors. Theoretical

of

connection may be very useful

to:

of

inputs where the change of an input

cuts

down the likelihood that two events

to

detect communications errors caused

should

an input is likely to turn on and

be

setup

so

that any activity

to

limit responses from a module. This

a

module has produced an output response:

Continuous Output Change

if

the following

on

the input lines

off

quickly and constantly,

is

Command:

Response:

With the Continuous Timer set
after each response before resuming scanning the digital

$1

CT+00005.00

*

to 5 seconds, module

#1

will pause for 5 seconds

110

lines. This prevents

6-10

1700

USERS

MANUAL

the module from hogging the communications bus in response to continuously
changing input lines.

G)

Continuous Input

The M1711/1712 modules may be

Mode

set

to

a special mode called Continuous Input

Mode which allows the module to respond to data transmitted by another module.

A

module in Continuous Input Mode may be paired with a module in Continuous

Output Mode to provide digital data transfer without

a

supervisory host. Figure

6

shows the simpIest connection.
(Figure 7)

Module

A.

Module

CONTINUOUS

OUTPUT

TIM3

MODE

#1

is setup in Continuous Output Timer Mode as described in Example

#1

will read the state of the digital inputs and produce data messages

CONTINUOUS

IN PUT
IN PUT

ADDRESS

4

on the communications bus. In this application, setting the Continuous Timer to

zero will produce the fastest response to input changes.

Module
are assigned as outputs. In continuous input mode, module

#2

is setup

for

Continuous Input Mode. The digital

I/O

lines

of

#2

will use the data

module

#2

from module #1 as a command to control the digital outputs. The net effect is that
the outputs of module

For example, an output message from module #1 might

*1

DIAOA059 (59

Module

#2

in Continuous Input mode will interpret this data as a Digital Output

#2

are controtled directly by the inputs of module

look

like:

is

checksum}

#l.

command. Internally, the continuous input module will translate fhis data and

perform the same function as:

$1

DOSFSFAD (AD

is

checksum)

I

Note that the original data

that a high input

at

module

the state of the digital inputs on module

module

#2.

'AOAO'

is complemented

#1

appears as a high output at module

#1

to

'5F5F'. This is necessary

is recreated at the digital outputs of

#2.

As

a result,

so

Since module #1 is continually outputting data on the communications lines, any

of

changes in the state

module

To setup module

#2

and the output lines will change to reflect the new state.

#2

the digital inputs on module

for Continuous Input Mode:

#1

will be transmitted

to

Continuous

1)

Setup the module for an address different from the Continuous Output

In

module.

The Continuous Input module will be setup for address

this example, the Continuous Output module is setup for address '1'.

InpuVOutput

'2':

6-1

1

Command:
Response:

Any address may be used for the Continuous Input module as
different from module

The communications setups for
with identical baud rate and panty settings. Also, the word length setup must be

identical.

2)

Assign the digital

Command:
Response:

3)

The Continuous Input module must

(CIA). This address
address is necessary

data

on

the communications bus. The full purpose

demonstrated in the next few examples. In this case, module

respond to data from module #l. Character
Input Address:

Com m and
Response:

The input address '31' is stored in nonvolatile memory.
the Read Input Address command:

$1

SU32070102

*

#I.

I/O

lines to be outputs:

$ZAIOFFFF

*

is

different from the normal communications address. This

so

that the continuous input module may selectively read

:

$2

Ct A3

*

1

both

modules must match. They must

be

assigned a Continuous Input Address

of

'1'

or

ASCII '31' is

It

can be read back with

long

as it is

be

setup

the CIA will be

#2

is setup to

the

Continuous

Command:
Response:

Enable the Continuous lnput Mode with the Continuous Mode Input

4)

command:

Command: $2CMI

Response:

The Continuous mode is saved in nonvolatile memory.
After the Continuous Input module has been setup, it may be connected to the

continuous output module as a stand-alone pair. Since all setup data is stored in

nonvolatile memory, the input-output pair will initialize automatically upon power-

up.

No

host is necessary for the continuous input-output function.

$2RIA

3

1

*

6-12

H)

Figure 8 shows a system, with

two modules set

1700

Multiple Continuous Input/Output

USERS

for

MANUAL

two

Continuous Input Mode: (Figure

IN

PUSS

modules set for continuous output mode and

8)

OUTPUTS

CONTINUOUS

OUTPUT

This system is similar-to example E except that 2 input-output module pairs share
the same communications line. Modules
output as detailed in example
their respective digital

A

typical output data stream would be:

'lD1812386

*2DIAOAOCEl

Module

(CIA)

from module
will ignore the data

Module

(CIA)

communications
Therefore the outputs

up to

bus.

#3

is

set for Continuous Input mode with the Continuous Input Address

equal

to

ASCII

#1

#4

is set for Continuous Input mode and its Continuous

is equal to ASCII

124

pairs

110

'31'

and use the data

from

bus

and responds only

of

of

modules may be linked together on a single communications

B.

This pair

lines and output the data on the communications bus.

(86

is

(CB

is

or character

as

a command

module

module

'32'

#2.

or

character

#4

will follow the inputs

#I

and

#2

of

M1712's

are setup

constantly read the state of

for

continuous

checksum)

checksum)

'1'.

This module will pick off the output data

to

set its output lines. Module

Input

'2'.

It

examines the data on the

to

data containing the address

of

module

#2.

#3

Address

'2'.

In theory,

CONTINUOUS

INPUT

I)

Bidirectional Continuous InputlOUtput

To

provide bidirectional data transfer from

pairs of modules and

OUTPUTS

two

communications links: (Figure

Continuous

one

location

Input/Output

to

another, simply use

9)

CONTINUOUS

IN

PUT

CIA=31

6-13

two

IN

PUTS

J)

Multiple Outputs

The output

than one continuous

Addresses

CONTINUOUS

OUTPUT

data

from a Continuous

(CIA): (Figure

CONTINUOUS

INPUT

CIA=

31

input

module

10)

CONTINUOUS

INPUT

CONTINUOUS
OUTPUT

Output

by

module

assigning the correct Continuous Input

may

be

used

to

control more

CONTINUOUS

IN

PUT

CONTINUOUS

INPUT

INPUTS

OUTPUTS

OUTPUTS

OUTPUTS

6-14

1700

USERS

MANUAL

In this system, module
are setup for Continuous Input. The three Continuous Input modules are
setup with a Continuous Input Address (CIA) of ASCII 31 or character
means that each of these three modules
an output command. The outputs of modules
data of module

Continuous

A module in continuous input mode will respond to data in the form of:

*I

D180F096

This is typical
module. The
The Continuous Input Module will respond to
read data from module
which data strings will be examined
command
case, to allow the module to respond

a

co m m

nd

#1.

Input

of

'1'

denotes the address

is

used

:

Command:

Response:

The number
An important consideration in constructing

make sure that all modules tied to the communications bus have unique address

as specified by the

modules in a normal polled manner. This greatly simplifies setup and debugging.
The Continuous Input Addresses (CIA) may be
the polled address.

'31'

is the ASCII code

#I

is set for Continuous Output mode. Modules

will

accept the data from module

2,

3

and 4 will replicate the input

Protocol

a

data string that may

#1.

to specify the ASCII code for the address character. In this

$2ClA31

*

SU

command. This allows an intelligent host

Notes

be

produced by a continuous output

of

the module producing the data stream.

this

data only

The Continuous Input Address (CIA)

by

the Continuous Input module. The CIA

to

data with the address tag

for

character '1'.

a

continuous inpuUoutput system

set

to

if

it

any value independent

is programmed

is

2,

3

&

'1'.

This

#1

used to specify

'l',

use the

is

to

use

the

4

all

as

to

to

of

Table

of

ASCll

characters

Hexadecimal (Hex), andBinary.Claret

(A) and

their equivalent values in

(*)

represents Control

Appendix

ASCII

Decimal

function.

(D),

A

Table

A

^@

"A

"B

^c

"D

"E

"F

"G

"H

"I

"J

"K
"L

"M

"N

"0

"P

"Q

"R

"S

"T

"U

nV
"W

"X

"Y

"Z

"1

"\

"I

M

A

-

!

#

$

%

&

(

1

+

i

0

1

Hex

D

0

00

1 01
2 02

3

03
4 04
5 05

06

6

7

07

8 08
9 09

10

OA

11 OB

oc

12
13

OD

14

OE

15

OF

16 10
17 11
18 12
19 13

20

14
21 15
22 16
23 17

24

18

25

19
26 1A
27 1B
28 1C
29 1D
30 1E
31 1F
32 20
33 21

22

34
35 23
36 24
37 25
38 26
39 27
40 28
41 29
42 2A
43 2B
44 2c

2D

45
46 2E
47 2F
48

30

49 31

Binary

00000000

00000001
0000001

0000001

000001
00000101
000001 10
000001 11

00001000

00001001
00001 010
0000101 1
00001 100
00001 101
00001 110
00001
0001
0001 0001
0001 0010
0001 001
0001 01
0001 01 01
0001 01 10
0001 01 11
0001 1000
0001 1001
00011010
00011011
00011100
0001 11 01
0001 11
000111 11
001
001 00001
001
00100011
001 001
001 001 01
00100110
00100111
001 01

00

101
00101 01
00101011
001 01 100
001 01 101
00101 110
00101 111

001 10000
001 10001

0

1

00

I1

1

0000

1

00

10

00000
00010

00

000
00

1

0

D

128 80
129 81 10000001
130 82 10000010
131 83
132 84 10000100
133 85 f0000101
134
135 87 10000111
136 88
137 89 10001001
138 8A 10001010
139 88 10001011
140 8C 10001100
141 8D
142 8E
143
144 90
145 91 10010001
146 92 10010010
147
148 94 10010100
149 95 10010101
150 96 10010110
151
152
153 99 10011001
154 9A 10011010
155
156 9C 10011100

157
158 9E 10011110
159 9F 10011111
160 A0 10100000
161 A1 10100001
162 A2 10100010
163 A3 10100011
164
165 A5 10100101
166 A6 10100110
167 A7
168 AS 10101000
169 A9 10101001
170 AA 10101010
171 AB
172 AC 10101100
173 AD
174
175
176
177 B1 10110001

Hex Binary

10000000

I0000011

86

10000110
10001000

10001101
10001110

8F

10001111
10010000

93 10010011

97 10010111

98

10011000

9B 10011011
9D 10011101

A4 10100100

10100111

10101011
10101101

AE

10101110
10101111

AF

BO

10110000

A-2

1700

A

D

2

50 32 00110010
51

3

4

52 34 00110100

5

53

6

54 36 00110110

7

55

8

56 38 00111000

9

57 39 00111001

58 3A 00111010

59 3B 00111011

<

60

-

-

61 3D 00111101

>

62 3E 00111110

?

63 3F 001111fl

64

0

A

65

B

66 42 01000010

C

67 43 01000011

D

68 44 01000100

E

69 45 01000101

F

70 46 01000110

G

71 47 01000111

H

72 48 01001000

I

73

74 4A 01001010

J

K

75 4B 01001011

L

76 4C 0~001100

M

77 4D 01001101

N

78 4E 01001110
79 4F 01001111

0

P

80

Q

81

R

82 52 01010010

S

83 53 0~010011

T

84

U

85

V

86

W

a7

X

88 58 01011000

Y

89 59 01011001

Z

90
91

I

\

92 5C 01011100

93

I

94
95 5F 01011111

-

96

a

97 61 01100001

b

98 62 01100010

c

99 63 01100011
100 64 01100100

d

101 65 01100101

e

f

102 66 01100110

103 67 01100111

9

h

104 68 01101000

i

105 69 01101001
106

j

USERS

Hex

Binary

33

00110011
35 00110101
37 00110111

3C 00111100

40 01000000
41 01000001

49 01001001

50

0<010000

51

01010001

54

01010100

55

01010101

56

01010110
57

oioioi11

5A

01011010

5B

01011011
5D 01011101

5E

010111f0

60

01100000

6A

01101010

MANUAL

D

178
179
180 B4 10110100
181
182
183 B7
184 B8 10111000
185 ~9
186 BA 10111010
187 BB
188

189 BD 10111101
190 BE 10111110
191
192 CO 11000000
193 C1 11000001
194
195
196
197
198 C6 llOOOflO
199 c7 11000111
200 C8 11001000
201 c9 11001001
202 CA 11001010
203 CB 11001011
204 CC 11001<00
205
206
207
208 DO 11010000
209 D1
210 D2 11010010
211
212
213
214
215 D7
216
217 D9 11011001
218 DA
219 DB
220
221
222 DE 11011110
223 DF
224 EO 11f00000
225 El 11100001

226

227

228
229
230

231 E7
232 E8 11101000
233
234 EA 11101010

Hex

Binary
B2 10110010
B3 10110011

B5 10110101
B6 10110110

10110111

ioiiiooi

10111011
BC 10111100

BF 10111111

C2

11000010
C3 11000011

C4

11000100

C5

11000~01

CD 11001~01

CE

11001410
CF 11001.111

11010001
D3 11010011

D4 11010100
D5 11010~01
D6

11010110

11010111
D8 11011000

11011010

11011011
DC 11011100
DD 11011101

11011111

11100010

E2
E3 11100011
E4 11100100

E5

11100101

E6

11100110

11100111
E9 11101001

A

D

Hex

k

107

6B 01101011

1

108

6C

rn

109

6D

n

110

6E

o

111

6F

p

112 70 01110000

q

113

71

r

114 72

s

115

73

t

116 74

u

117

75

v

118

76 01110110

w

119

77

x

120 78 o1iiiaoo

y

121 79 01111001

z

122

7A

{

123 7B 01111011

I

124 7C 01111100

}

125

7D 01111101

-

126 7E 01111110
127 7F 01111111

Binary

01101100

01101101

01101110
01101111

01110001

01110010

01110011
01110100

01110101
01110111

01111010

ASCII

Hex

D
235
236
237
238
239
240
241
242
243
244 F4
245
246
247 F7 11110111
248
249
250
251
252
253
254 FE 11111110
255

Binary

11101011

EB

EC

11101100

11101101

ED

11101110

EE
EF

11101111

FO

11110000

F1

11110001

F2

11110010

F3 11110011

11110100

F5 11110101

F6

11110110

F8

11111000

F9

11111001
11111010

FA

FB 11111011

FC

11111100

FD

11111101

FF

11111111

Table

A-3

M1770

64

Channel

Appendix

Digital

I/O

B

Board

The Mi770 Digital
capability for computers, modems, and other devices with standard serial
ports. Commands communicated over standard RS-232 or RS-485 links
may be used

The Mi 700 is designed
relay racks. Up
with ribbon cable connectors.

The

64

combination designated by the user. The inputloutput configuration may
be changed at any time through the communications port. The
assignments are saved in nonvolatile memory and are autornaticly loaded
when the unit is powered up.

Getting

RS-232,

The MI770 contains drivers
ports. The M1770 must be configured
connected to the host. The M1770 has a 12-pin header near the edge of the
board marked
make sure the three jumpers are installed adjacent
To configure the board for RS-485, make sure the jumpers are adjacent

to

the RS-485 label.

Pin

Connections

The host interface connection is wired

to

I/O

channels may be configured to be inputs or outputs in any

Started

RS-485

I/O

interface is designed

control

to four 16-channel racks may be connected

RS-232/RS-485.

or

read up

to interface to industry-standard solid-state

Selection

to

to

connect

To

64 digital

to

to

the desired interface before

configure the board for RS-232,

to

the six-pin terminal plug:

to

provide remote

I/O

channels.

either RS-232

to

the RS-232 label.

to

the M1770

or

RS-485

110

I/O

it

is

:

Pin 1
supply must provide

Pin 2:
When grounded, the board assumes the default communications setup of

300

Pin
configured for RS-485, this pin is the DATA connection.

3

Pin 4:
configured for RS-485, this is the DATA*,
connection.

Pin
grounded, the M1770 will be in Continuous Mode.

Pin
signal ground for the serial port.

Output Connections
The digital
connectors. The output connections are made
industry-standard 16-channel solid-state relay racks. The connector
nearest the edge of the board (J2) is wired

+5V

This

is

the power supply connection for the board. The power

+5V

+/-

5% at

DEFAULT' This pin

baud, any address, no parity (See Chapter 1).

3:

DATA/TX This pin

is

the

Transmit output from the M1770.

DATA*/RX This pin is a serial port connection.

For

RS-232, this

5:

CONT'

6:

GND This is the power supply ground connection.

This pin is normally

I/O

connections are made through

is

is

is

100

mA.

normally left open

a serial port connection.

the receive input of the M1770.

Ieft

open or pulled up to

to

the lowest-order

or

pulled high

If

the board is

For

RS-232,

If

the board

or

the negative data

+5V.

It

is also the

the

four ribbon cable

to

be compatable with

16

to

When

bits.

+5V.

pin

is

B-2

1700

52

-

Pin Sianal
17

I9

21

23

25

27

USERS

BOF

BOE
BOD

BOC

BOB

BOA

29 B09

31
33

35
37

39

41

43

45

47

All

even

All

pins are

other

pins

BOB
B07

B06

B05
B04
B03
B02
B01
BOO

connected

are

no connection.

MANUAL

to

GND

53

-

Pin

17

19

21

23

25
27

29

31

33 B17
35 B16
37

39

41 B13
43 BIZ
45 B11

47

All

even

pins are

All

other pins

Sianal

B1

F

B1

E

B1

D

B1

C

B1

B

B1

A

B19

B18

B15
01

4

BIO

connected

are

no connection.

to

GND

H1770

J4

-

Pin

17
19 B2E

21

23 B2C
25 B23

27

29 B29
31 B28
33 827
35 B26
37 B25
39 B24
41 B23
43 822
45 B21
47 820

Even

pins

All

other pins are no connection.

Siand

B2

B2D

B2A

18-50

F

are connected

64

Channel

to

GND

Digital

I/O

Board

B-3

J5

-

Pin

17

19 B3E

21 B3D

23

25 B3B
27 B3A
29 B39

31

33 837

35 B36

37
39
41 B33

43

45
47 B30

Even

pins

All

other

Sianal

83

F

B3C

B38

B35

834

B32

83

1

18-50

pins

are connected

are no connection.

to

GND

M1750

The

Mi750

Opto-22

with

the

Hook-Up:

Plug

the

the header and latch the board

is designed

16

or

24

channel solid-state relay backplane or equivalent backplanes

standard pin-out.

M1750

into the backplane header. Be sure the board is centered over

to

interface directly

24-Channel

to

the header.

to

an

MSS-16

Appendix

Digital

I/O

IlO

Board

module rack

C

or

M1750

The
desired communications link with the three shorting bars near the edge

M1750.

Move the three shunts

If

RS-232

output pin. The DATA'/RX pin is the receive input.

If

RS-485

Data' (Data

The

M1750

the

GND

should be

110

lines are connected

The odd-numbered pins

pad being

contains line drivers

Move the fhree shunts to the

to

the

is

selected, the DATMX pin on the 6-pin connector is the transmit

is

selected, connect the Data (Data

-)

line

to

the DATA*/RX pin.

is powered by a regulated

and

+5

Vdc

pins. For proper operation, relays used in a backplane

+5V

types.

to

the odd-numbered pins on the header connector.

are

#I.

All

even-numbered pins are connected

for

both

RS-232

'RS-232'

'RS-485'

closest to the edge

position

c)

4.75

to

to

line to the DATMX pin and the

5.5V

and

RS-485.

position

select

power supply connected to

of

the board with the square

to

RS-485.

to

ground.

Select the

select

RS-232.

of

the

Specifications are subject to change without notice.
All Keithley trademarks and trade names are the property of Keithley Instruments, Inc. All other

trademarks and trade names are the property of their respective companies.

Keithley Instruments, Inc. 28775 Aurora Road • Cleveland, Ohio 44139 • 440-248-0400 • Fax: [phone]

1-888-KEITHLEY (534-8453) • www.keithley.com

Sales Offices: BELGIUM: Bergensesteenweg 709 • B-1600 Sint-Pieters-Leeuw • 02-363 00 40 • Fax: [phone]

CHINA: Yuan Chen Xin Building, Room 705 • 12 Yumin Road, Dewai, Madian • Beijing 100029 • 8610-6202-2886 • Fax: [phone]
FINLAND: Tietäjäntie 2 • 02130 Espoo • Phone: [phone] • Fax: [phone]
FRANCE: 3, allée des Garays • 91127 Palaiseau Cédex • 01-64 53 20 20 • Fax: [phone]
GERMANY: Landsberger Strasse 65 • 82110 Germering • 089/84 93 07-40 • Fax: [phone]
GREAT BRITAIN: Unit 2 Commerce Park, Brunel Road • Theale • Berkshire RG7 4AB • 0118 929 7500 • Fax: [phone]
INDIA: Flat 2B, Willocrissa • 14, Rest House Crescent • Bangalore 560 001 • 91-80-509-1320/21 • Fax: [phone]
ITALY: Viale San Gimignano, 38 • 20146 Milano • 02-48 39 16 01 • Fax: [phone]
JAPAN: New Pier Takeshiba North Tower 13F • 11-1, Kaigan 1-chome • Minato-ku, Tokyo 105-0022 • 81-3-5733-7555 • Fax: [phone]
KOREA: 2FL., URI Building • 2-14 Yangjae-Dong • Seocho-Gu, Seoul 137-888 • 82-2-574-7778 • Fax: [phone]
NETHERLANDS: Postbus 559 • 4200 AN Gorinchem • 0183-635333 • Fax: [phone]
SWEDEN: c/o Regus Business Centre • Frosundaviks Allé 15, 4tr • 169 70 Solna • 08-509 04 679 • Fax: [phone]
SWITZERLAND: Kriesbachstrasse 4 • 8600 Dübendorf • 01-821 94 44 • Fax: [phone]
TAIWAN: 1FL., 85 Po Ai Street • Hsinchu, Taiwan, R.O.C. • 886-3-572-9077• Fax: [phone]

© Copyright 2001 Keithley Instruments, Inc.

Printed in the U.S.A.

4/02