Black Box 945 User Manual
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How To Use

Data Communications

with the Watlow

Series 945

User's Manual

Watlow Controls, 1241 Bundy Blvd., P.O.Box 5580, Winona, MN 55987-5580,Phone:507/454-5300,Fax:507/452-4507

W945-SA50-9210

$5.00

March, 1992

Made in the U.S.A.

Supersedes:

W945-SA40-9119

Printed on Recycled Paper

How to Use Data Communications

WATLOW Series 945

1

Contents

Page

Item

 

 

3

Data Communications and the Series 945

 

 

3

Hardware Interfaces Protocols

 

 

3

Communications Wiring

 

 

4

RS-422A Interface Pinouts

Figures

Item

5

RS-423A Interface Pinouts

 

 

 

(RS-232CCompatible)

1

RS-422 Interface Wiring

6

EIA-485 Interface Pinouts

2

RS-423 Interface Wiring

6

Connecting the Control and Computer

3

EIA-485 Interface Wiring

7

Setting Hardware Protocol Switches

4

RS-422/RS-423 Switch Selection

7

Network Connections

5

General Message Syntax Example

7

Series 945 Communication Parameters

6

XON/XOFF "=" Command Example

8

Communications Setup Parameters

7

XON/XOFF "?" Command Example

10

ASCII and Series 945 Information

8

ANSI X3.28 "=" Command Example

11

Series 945 General Message Syntax

9

ANSI X3.28 "?" Command Example

11

Message Syntax

10

Data Logging Interface Wiring

11

Data Rules

11

Table Printout Example

12

Command List

12

Chart & SPC Printout Example

12Example Format

13XON/XOFF Protocol for RS-423A

13

Start and Stop Communicating with the

Tables

Item

 

Series 945 and XON/XOFF

 

 

14

XON/XOFF "=" Command Example

1

Setup Menu Prompts and Descriptions

15

XON/XOFF "?" Command Example

2

ASCII Character Set

16

ANSI X3.28

Protocol for RS-422 & EIA-485

3

ASCII Control Characters (Partial Set)

16

Device Address

4

Address to ASCII Conversion

16

Starting Communications in ANSI X3.28

5

"?" Command Data and Responses,

17

Stopping Communications in ANSI X3.28

 

Partial Set

17

ANSI X3.28

"=" Command Example

6

"=" Command and "?" Command Data

18

ANSI X3.28

"?" Command Example

7

Printer Troubleshooting

19"?" Command

20"=" Command

22Data Logging

23Table Printout

23Statistical Process Control - SPC

24The Difference Between Control and Specification Limits

25Chart and SPC Printout

26NAKs and Error Codes

26User Responsibility

27Index

2

WATLOW Series 945

How to Use Data Communications

Data Comm

How to Use Data Communications with the Watlow Series 945

This manual is a supplement to the Series 945 User's Manual. It is for users with the data communications option. Use in conjunction with the Series 945 User's Manual.

This is expert user-levelmaterial and requires previous experience with data communications.

Two Serial Hardware Interfaces and

Two Software Protocols

Depending on your units model number, you may have one of two hardware interfaces:

1)RS-422A for a "multidrop" or (multiple device) network, up to ten devices total; with 4000 ft. network length limit, orRS-423A (RS-232Ccompatible) for one on one communication with a 50 ft. network length limit with a 945 and a host computer(945A-XXXX--B000).SelectingRS-422AorRS-423Ais user selectable via internal switches. See Page 7.

2)EIA-485 (945A-XXXX-D000)also for a multidrop network, up to 32 addresses total, and with a 4000 ft. network length limit.

There are two protocols available to you. Depending on the type of network you need, you must use the correct combination of interface and protocol.

We use ANSI X3.28 Protocol, based on ANSI X3.28 - 1976 Subcategories 2.2, and A3, with theRS-422AandEIA-485interface to run a multiple device network. We also useXON/XOFF Protocol, a simpler protocol, to run a two device network with anRS-423Ainterface. XON/XOFF will also work with theRS-422Aand EIA485 interface, but the network is limited to two devices (one computer or printer and a Series 945). XON/XOFF Protocol requires no responses to messages like the ANSI X3.28 Protocol does. Likewise, ANSI X3.28 Protocol, which provides a response to every message, will work with theRS-423interface. But again you are limited to one Series 945 and a host computer or printer.

To select which protocol you are going to use, go into the SETUP menu and use the MODE key to advance to the Prot parameter. Select eitherFULL, for ANSI X3.28 2.2 - A.3, orOn for XON - XOFF.

If you are using ANSI X3.28 Protocol, choose an address number for the control under the Addr parameter following the Prot parameter. This parameter will only appear if Prot = FULL.

Communications Wiring

To connect your Series 945 to a computer or printer, use the next three pages as a reference. Your computer or printer hardware manual will provide more detailed serial port pin information. Also refer to the noise prevention section in Appendix 1 of the Series 945 User's Manual. In the often noisy environments of industrial locations, it is important not to take noise isolation lightly.

How to Use Data Communications

WATLOW Series 945

3

RS-422A

RS-422AInterface Pinouts

945A-XXXX-B000

The RS-422Acommunications uses a four wire (full duplex) system. There are two separate lines for transmitting, and two lines for receiving data between the computer and the Series 945. WithRS-422Ayou can have from one to ten Series 945 controls connected to a single computer.

This diagram is a typical wiring example. The connections on the host computer may vary depending on models. Refer to your computer user's manual for more information.

Figure 1 -

RS-422AInterface,

Pin Designations.

Series 945 #1

Series 945 #10

NOTE:

19

T +

Twisted Pair Wire

 

 

 

20T -

21R +

22R -

23

Signal Common

(Optional)

 

 

Host Computer

 

 

 

(rear view)

 

19

T +

Twisted Pair Wire

 

 

 

T -

 

 

20

 

 

R +

 

 

21

 

 

R -

 

 

22

 

 

Signal Common

 

 

23

DB-9female

 

(Optional)

 

 

 

 

 

connector

 

 

 

(viewed from wire side)

Com

 

 

 

1

 

 

6

 

 

 

 

2

 

 

7

 

 

 

R +

3

 

 

8

T -

 

 

 

 

 

R -

4

 

 

9

T +

 

 

 

 

 

 

5

The Electronic Industry Association (EIA) RS-422Astandard recommends a maximum 4000 ft. total network distance.

4

WATLOW Series 945

How to Use Data Communications

RS-423A

RS-423AInterface Pinouts(RS-232CCompatible)

945A-XXXX-B000

The RS-423Acommunications uses a three wire (full duplex) system. There is a separate line for transmitting, a line for receiving data, and a line for signal common between the computer and the Series 945. WithRS-423Ayou can have only one Series 945 control connected to a single computer or printer.

This diagram is a typical wiring example. The connections on the host computer may vary depending on models. Refer to your computer user's manual for more information.

R, and RLSD together. and CTS together. puter's user manual.

Host Computer

(rear view)

DB-25female

 

 

connector

14

1

 

(viewed from wire side)

2

15

 

 

 

 

3

 

16

3

 

4

 

 

 

17

4

 

5

 

18

 

6

DTR (Data Terminal Ready)

19

7

2

 

0

 

218

9

2210

2311

2412

2513

 

 

20

T

 

 

Jumper to Signal Common

 

 

21

 

 

R

 

 

 

 

22

 

945

#1

Signal Common

 

23

 

 

 

 

T

R

RTS (Request To Send)

CTS (Clear To Send)

DSR (Data Set Ready)

Com

RLSD (Received Line Signal Detector)

Figure 2 -

RS-423AInterface,

Pin Designations.

NOTE:

The Electronic Industry Association (EIA) RS-423Astandard recommends a maximum 50 foot total point-to-pointdistance.

How to Use Data Communications

WATLOW Series 945

5