Rockwell Automation 1771-DA, D17716.5.13 User Manual

Download

AllenBradley

ASCII I/O Module

(Cat.

No. 1771-DA)

User Manual

To Our Customers 11. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Overview of This Manual 11. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Intended Audience 11 Notational Conventions 11 Some Tips on Using This Manual 12 Typical

Applications

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13. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Getting Started With Y

PLC2 Family Processors 22. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

What You Need to Get Started 22 Reading Data from Your ASCII Device 210 Writing

Data to Y PLC3 Processors 218 What You Need T Reading Data from Your ASCII Device 228 Writing

Data to Y

our ASCII Device 214. . . . . . . . . . . . . . . . . . . . . . . .

o Get Started

our ASCII Device 232. . . . . . . . . . . . . . . . . . . . . . . .

our ASCII Module

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21. . . . . . . . . . . . . .

218. . . . . . . . . . . . . . . . . . . . . . . . . .

Choosing Module Features 31. . . . . . . . . . . . . . . . . . . . . . . .

Chapter Choosing Choosing the Mode of Module Operation, IW1(0204) 313 Using BCD Delimiters (Report Generation Mode, Only), IW4(1016) 314

Justifying Margins, IW3(03) 315. . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Using the EndofString Delimiter, IW3(1016) 317 Setting String Length, IW2(0013) 318 Determining Block Transfer Length 320 Removing the Fill Character (Data Mode, Only), IW4(1016) 321 Removing Header and Trailing Characters, IW4(0003, 0407) 323 Choosing Choosing Transmission Mode, IW1(0507) 325 Choosing Selecting Delay for Carriage Return, IW3(0607) 326 Setting Remaining Bits in IW1(1017) 326 Selecting Recording

Objectives

the Mode of Communication

I/O Buf

fer Size, IW3(0002) 324. . . . . . . . . . . . . . . . . . . . .

Single or Multiple T

the Number of Initialization W

Bit Settings in Initialization W

ransfers, IW2(17) 325. . . . . . . . . . . . . . .

31. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

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ords, IW1(0001) 329. . . . . . . .

ords 330. . . . . . . . . . . . . . . . .

Table of Contentsii

ASCII

I/O Module T

utorial 41. . . . . . . . . . . . . . . . . . . . . . . . . .

Chapter PLC2 Family Processors 42 Adding Setting Expanding Changing Justifying Demonstrating EndofString Delimiter 49 Removing the Fill Character 414 Removing Header and Trailing Characters 415 Demonstrating Data Conversion 417 Selecting Report Generation Mode, Data Conversion,

Formatting a SingleLine Message 421 Formatting a MultiLine Message 424 PLC3 Processors 427 Adding Setting Expanding Changing Justifying Demonstrating EndofString Delimiter 435 Removing the Fill Character 440 Removing Header and Trailing Characters 442 Selecting Report Generation Mode, Data Conversion,

Formatting a SingleLine Message 446 Formatting a MultiLine Message 449 Demonstrating Data Conversion 452 Summary 455

Objectives

Initialization Rungs Bits in Initialization W

the Number of Initialization W

the Module'

Data

and BCD Delimiter

Initialization Rungs Bits in Initialization W

the Number of Initialization W

the Module'

Data

and BCD Delimiter

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s String Length (Read, Only) 45. . . . . . . . . . . .

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s String Length (Read, Only) 432. . . . . . . . . . . .

41. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

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42. . . . . . . . . . . . . . . . . . . . . . . . . . . . .

ords 44. . . . . . . . . . . . . . . . . . . . . . . .

ords 45. . . . . . . . . . . . . . . .

47. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

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419. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

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427. . . . . . . . . . . . . . . . . . . . . . . . . . . . .

ords 430. . . . . . . . . . . . . . . . . . . . . . . .

ords 432. . . . . . . . . . . . . . . .

434. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

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443. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

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Handshaking 51. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Chapter Understanding Handshaking Fundamentals 51 Reading Status and/or Data from the Module 53

Objectives

51. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

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Function of Control and Status Bits 61. . . . . . . . . . . . . . . . . .

Chapter Command Words 61 Initialization Words 63 Status Words 613

Objectives

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61. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Table of Contents iii

Troubleshooting 71. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Chapter Recognizing How You Interpret Status Indicators 72 How You Interpret Codes in Status Word One 74 Testing the ASCII Module and Cables 77

Objectives

Initialization Errors

71. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

71. . . . . . . . . . . . . . . . . . . . . . . . . .

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PLC2 Family Processors A1. . . . . . . . . . . . . . . . . . . . . . . . .

Complete Getting Started Program, PLC2 Family A1. . . . . . . . . . . . .

Block Transfer Programming A3 Block Transfer Timing A5 Example Read (Only) Program A15 Example Write (Only) Program A18 Example Read/Write Program A19 Example Application Write Program A22 For PLC-3 Family Processor A26 Complete Getting Started Program, PLC-3 A26 Block Transfer Programming A30 Example Read (Only) Program A41 Example Write (Only) Program A45 Example Read/Write Program A47 Example Application Read/Write Program A50

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For PLC3 Family Processor B1. . . . . . . . . . . . . . . . . . . . . . .

Complete Getting Started Program, PLC3 B1. . . . . . . . . . . . . . . . . .

Block Transfer Programming B5 Example Read (Only) Program B16 Example Write (Only) Program B20 Example Read/Write Program B22 Example Application Read/Write Program B25

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ASCII Conversion Tables C1. . . . . . . . . . . . . . . . . . . . . . . . . .

Specifications D1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

To Our Customers

Preface

Overview of This Manual

This manual tells you in a tutorial manner how to install and use your ASCII module.

Chapter

4 Handshaking

6 T

 Appendix

Getting Started with Y

our ASCII Module

Choosing Module Features

ASCII Module T

Functions of Control and Status Bits

roubleshooting Y

Module

Entitled W

Read data from your ASCII module and write data to it using an industrial terminal

Choose module features so you can match your ASCII module with your ASCII device

utorial

our ASCII

Select and demonstrate module features, and format messages

Program the handshaking logic that controls communication between your ASCII module and your PC processor

Select desired features and read module status by describing the function of bits in command and status words

Interpret status indicators and status codes, and use a simple program to test your ASCII module.

Program block transfer communication and estimate the time required for read/write handshaking. W included numerous example programs

e W

ill Show Y

ou How T

e have

Intended Audience

Notational Conventions

 Index

Locate concepts and definitions in the text

We assume that you are familiar with operating and programming your Allen-Bradley controller. Because of the functions that your module performs, your programming skills should include file manipulation and message formatting. Refer to the Programming and Operations Manual for your PLC-2 family controller or to the Programming Manual for your PLC-3 controller.

Some chapters in this manual contain examples of how you enter data or commands. When you read these chapters, remember the following notational conventions:

Preface

To Our Customers

A symbol or word in brackets represents a single key you would press.

These include keys such as [ENTER], [SHIFT], or [

Spaces would be entered as shown, except that the space preceding and

following the brackets is not an entered space. (We put a space before

the left bracket and after the right bracket to make it easier to read). Numbers and capital letters not in brackets would be entered as shown. Punctuation such as commas, and symbols such as / would be entered

as shown.

For example, typical data and a typical command that you would enter on the industrial terminal keyboard are as follows:

Enter: ALLEN 123/AB[ENTER] (data)

Enter: DD,O3:0,[SHIFT]%A[ENTER] (PLC-3 command)

Some Tips on Using This Manual

We have included numerous examples of CRT displays resulting from data or commands that you enter. All CRT displays are shown with a shaded background. Enter all commands on the industrial terminal keyboard. The only exception is for some PLC-3 entries where we tell you to use the PLC-3 front panel.

Read chapters 1 and 2 before proceeding to other chapters of this manual that pertain to your needs. For example, you may want to use only selected module features (chapter 3) and read only selected bit descriptions (chapter 5).

We have developed forms to assist you in selecting module features and in troubleshooting. Make a copy of each of the following and refer to them as needed.

Initialization Words for Data Mode Form 5175, chapter 2 Initialization Words for Report

Generation Mode Form 5176, chapter 2 Command and Status Words Figure 5.2-5.4 chapter 5 Fault Status Table 6.E, chapter 6

Preface

To Our Customers

You will use several procedures frequently in the tutorial chapters of this manual. You may want to memorize the steps or have a reference copy of the following procedures:

Reading Data From Your ASCII Device Writing Data To Your ASCII Device Setting Bits in Initialization Words

Typical Applications

You can use an ASCII I/O module to input data to the processor from a data source such as a bar code reader, output messages from the processor to a display device, or bidirectionally exchange messages and/or data between an intelligent data terminal and the processor. Typical examples are as follows:

Type

Devices

Bar code readers

Keypads Input

Dotmatrix scrolling displays, terminals, or printers

Intelligent data terminals

Computers Input/Output

Device Applications

Input

Output

Input/Output

Part recognition, sorting, inventory control

Enter values, change data

Display warnings or diagnostic messages, print production reports

Enter values, change data, monitor or troubleshoot a process

Exchange data files

Chapter

Getting Started With Your ASCII Module

ASCII is the acronym for American Standard Code for Information Interchange. The standard includes a 7-bit code for 128 data and control characters.

With your ASCII I/O module you can transfer data, by means of the I/O scan, from an ASCII device to the PC processor data table, and vice versa. The module has two modes of operation, data mode and report generation mode. In data mode, you can transfer ASCII, BCD, or hex characters. Generally, use this mode to transfer data to the processor data table. In report generation mode, you can include BCD values in the string of ASCII characters. Generally, use this mode when you want to transfer messages.

You can use your ASCII module with any Allen-Bradley programmable controller that has an expandable data table, block transfer capability, and uses the 1771 I/O structure. If you use a PLC-2/20 controller (cat. no. 1772-LP2), your programming will be lengthier because its processor does not have file move or block transfer instructions.

Getting Started with Your ASCII Module is a hands-on exercise. By going step by step through two easy examples, you will quickly learn operation of your module’s basic features.

This chapter is divided into two sections, one for PLC-2 family processors, the other for PLC-3 processors. Proceed to the section that pertains to your processor.

21

Chapter 2

Getting Started with Your ASCII Module

PLC2 Family Processors

What You Need to Get Started

You will demonstrate the operation of your ASCII module by reading data from the industrial terminal to the processor data table, and by writing data from the data table to the industrial terminal. You will use your industrial terminal as an ASCII device for entering data (read), and for displaying data (write).

You will need to set up a PC processor with an I/O chassis, power supply, industrial terminal, cables, and your ASCII module. You will need about an hour to complete the tutorial exercises in this chapter, and about two hours to complete those of chapter 3, once you have the equipment operating properly.

Equipment That You Need

You will need the following equipment (Table 1.A) using your existing system and/or spare equipment.

Table 1.A Equipment

(PLC2 Family)

22

Equipment

ASCII I/O module

Industrial T

PLC2 Family Keytop Overlay

Alphanumeric Keytop Overlay

Processor Interface Cable

IT/DH Adapter Cable

Processor PLC2/20, 2/30

I/O Interconnect Cable 1777CB, CA

Local Adapter Module

ermination Plug

erminal 1770T3

I/O Chassis

Power Cable

Catalog Number

1771DA

1770KCB

1771KAA optional

1772TC

1770CB (figure 1.4)

1771A1, A2, A4

1771CJ, CK

1771AL

1777CP

Chapter 2

Getting Started with Your ASCII Module

Processor

MiniPLC2/15

Power Supply

Power Cable

1771P1

1771CL

Note: You must use battery back-up.

The ASCII module draws 1.3A from the backplane. Be sure that the total current drain of all modules in the chassis does not exceed the maximum for the backplane and power supply.

If you use an existing system, consider disconnecting all other chassis except the one containing your ASCII module. Disconnect field wiring arms from output modules for safety purposes.

How to Connect Your Equipment

Connect your equipment with the appropriate cables (Figure 1.1 for Mini-PLC-2/15 controllers, Figure 1.2 for PLC-2/20 or-2/30 controllers). Be sure that the end of your IT/DH adapter cable labeled CHANNEL B is connected to channel B on the industrial terminal.

23

Chapter 2

Getting Started with Your ASCII Module

1771-P1 Power Supply

1771-CL Power Cable

Figure 1.1 Connections

Mini-PLC-2/15 Processor

for MiniPLC2/l5 Controller

Module Group 1, Slot 1

1771-DA ASCII I/O Module

1771-A1, -A2, -A4 I/O Chassis

1772-TC Processor Interface Cable

See WARNING in section titled How to Connect Your Equipment." Using Channels

A & B

Channel A

1770-T3 Industrial Terminal (rear view)

Channel B

1770-CB IT/DH Adapter Cable

11817

1. Connect the power cable between the power supply and the I/O

chassis. The cable connects to the backplane of the I/O chassis behind the processor/adapter slot.

2. Connect the processor interface cable between the PC processor and

channel A on the industrial terminal.

3. Connect the IT/DH adapter cable between the ASCII module and

channel B on the industrial terminal.

24

Chapter 2

Getting Started with Your ASCII Module

1771-CK,-CJ PowerCable

Figure 1.2 Connections

PLC-2/30

Processor

1771-ALLocal AdapterModule

for PLC2/20 or PLC2/30 Controller

1772-TCProcessor InterfaceCable

1771-CA,-CB I/OInterconnect Cable

ModuleGroup1, Slot1

ChannelA

1771-DAASCII I/OModule

See WARNING in section titled How to Connect Your Equipment." Using Channels

A & B

1770-T3 IndustrialTerminal (rearview)

ChannelB

1770-CBIT/DH AdapterCable

1771-A1,-A2,-A4 I/OChassis

1777-CP TerminationPlug

11818

4. (PLC-2/20, -2/30, only) Connect the I/O interconnect cable between

the PC processor and the I/O adapter module

If the IT/DH adapter cable is too short or not available, make your own. It should not exceed 50 feet (Figure 1.4).

Using Channels A and B

You may or may not be able to connect cables to channels A and B at the same time depending on the revision of your industrial terminal.

25

Chapter 2

Getting Started with Your ASCII Module

Industrial terminals manufactured before May 1982 allow cross talk between channels A and B. As a result, data table values could be altered. Therefore, you should alternate cables between channels for the tutorials of this manual when using these terminals. When using a series A industrial terminal, you must alternate cables.

Your industrial terminal has a date code stamped in white on the upper right corner of the rear label. If your industrial terminal (cat. no. 1770-T3/TA series B) is date coded T 8218 or earlier, or is not date coded, alternate cables and observe the following warning:

WARNING: When cables are connect to channels A and B at the same time, cross talk between these channels could cause the processor to misread inputs and/or misapply outputs, with possible damage to equipment and/or injury to personnel. For this reason, do not remove the slide bar that prevents you from connecting cables to channels A and B at the same time.

If your industrial terminal (cat. no. 1770-T3/TA series B) is date coded T 8219 or later, you can use channels A and B at the same time.

If alternating between channels A and B, connect the 1770-CB cable to channel B when using the industrial terminal in alphanumeric mode as a data terminal. Connect the 1772-TC cable to channel A when using the industrial terminal in PLC-2 (ladder diagram) mode.

As an alternative, use a second industrial terminal in alphanumeric mode on channel B, or use a Silent 700 data terminal. Connect either to the 1770-CB cable.

Checking ASCII Module Configuration

Your module is configured for RS-232-C operation when shipped from the factory. If you suspect that its internal configuration (settings of internal programing plugs) has been altered, you should check module configuration (refer to section titled Choosing the Mode of Communication in chapter 3). Do this as follows:

26

1. Remove covers from the module’s printed circuit board.

Chapter 2

Getting Started with Your ASCII Module

2. Locate the programming plugs and set them according to RS-232-C

without control lines (figure 2.8).

Entering the ““Getting Started Program””

You may want to record on tape the ladder diagram of your application program before proceeding because you will need to load ASCII logic into a cleared memory for chapters 1 and 3.

Using your industrial terminal, enter the ““Getting Started Program”” (Figure 1.3) into processor memory. At this point, you do not need to understand how the program works, but you should enter it exactly as shown.

27

Chapter 2

Getting Started with Your ASCII Module

Figure 1.3 Getting

LADDER DIAGRAM DUMP

020

252

020

063

15 252

252

327

000

063

17 200

200

Started Program" (PLC2 Family)

START

200

PUT

000

200

063

TON

.01

PR 300 AC 000

035

03500252

251

063

000

020

063

000 02001252

02001252

100

247

200

020

200

OFF 15

200

OFF 15

020

OFF 00

020 U

OFF 00

200

ON 16

200

ON 16

28

Chapter 2

Getting Started with Your ASCII Module

011

BLOCK XFER READ

DATA ADDR:

MODULE ADDR:

BLOCK LENGTH:

FILE:

BLOCK XFER WRITE

DATA ADDR:

MODULE ADDR:

BLOCK LENGTH:

FILE:

252 - 271

200 - 217

030

111

031

111

011

111

020

END 00460

NOTE: Configure the data table for two racks using [SEARCH][5][0] before entering this program.

Installing Your ASCII Module

Be sure that power to the I/O chassis is turned off when installing (or removing) your ASCII module as follows:

1. Remove power from the I/O chassis.

2. Insert the ASCII module in rack 1, module group 1, slot 1. The

program makes the processor communicate with the ASCII module at that specific location. (If you must use another rack location and are familiar with block transfer operation, change the rack, group, and slot number of the module address in the block transfer read and write instructions, accordingly.)

3. Turn on power to the I/O chassis. Three LED indicators on the

ASCII module illuminate momentarily. Their functions are:

FAULT: Normally off. This red LED indicator illuminates when the module detects an internal fault.

29

Chapter 2

Getting Started with Your ASCII Module

BUFFER FULL: Normally off. This yellow LED indicator illuminates when the input buffer becomes full.

CHANNEL ACTIVE: This green LED indicator illuminates when the industrial terminal is on, properly connected to the ASCII module’s interface port, and set for alphanumeric mode.

Reading Data from Your ASCII Device

In this demonstration, you will enter data and observe how it is stored in the processor data table. You will use the industrial terminal in alphanumeric mode as an ASCII data terminal when you enter data. Then you will change the industrial terminal to PLC-2 mode and observe the transferred data by displaying the contents of the block transfer read file.

You will use the following procedures:

Procedure

Set your industrial terminal to alphanumeric mode

Enter your data

Set your industrial terminal to PLC2 mode

See how data is stored in the data table

ou W

ill

Later in this chapter and in chapter 3 you will combine these procedures with others. The order in which you will perform them may vary.

Even if you are familiar with these procedures, we suggest that you read them completely. If you deviate from them, proper operation may not occur.

210

If you have not already done so, load the “Getting Started Program” (Figure 1.3) into processor memory.

Procedure P1 Set Your Industrial Terminal to Alphanumeric Mode

1. Turn on the industrial terminal.

2. Insert the Alphanumeric Keytop Overlay (cat. no. 1770-KAA).

Chapter 2

Getting Started with Your ASCII Module

To avoid switching keytop overlays every time you change the industrial terminal operating mode, you can label numbers, letters, and [RETURN] on the corresponding keytops of the PLC-2 family overlay.

3. Select alphanumeric mode.

Press 12 on the keyboard

The ASCII module’s CHANNEL ACTIVE LED illuminates.

4. Set the communication rate to 300 baud.

Press 13 [RETURN]

The cursor in the upper left corner of a blank screen tells you the terminal is ready for your input.

5. Change the processor mode select switch to the RUN/PROG

position. (Failure to do this step now will prevent a transfer.)

Procedure P2 Enter Your Data

1. Be sure the processor mode select switch is in the RUN/PROG

position.

2. Enter data such as your first name followed by a couple of numbers.

Enter 11 characters including a space between your name and numbers (Table 1.B).

211

Chapter 2

Getting Started with Your ASCII Module

Table 1.B Commonly

ASCII Hex ASCII Hex ASCII Hex

space 20 0 30 1 31 2 32 3 33 4 34 5 35 6 36 7 37 8 38 9 39

Used Data Characters

A 41 B 42 C 43 D 44 E 45 F 46 G 47 H 48 I 49 J 4A K 4B L 4C M 4D

N 4E O 4F P 50 Q 51 R 52 S 53 T 54 U 55 V 56 W 57 X 58 Y 59 Z 5A

The industrial terminal displays the characters as you enter them. If characters are not displayed, check the program that you loaded into memory. If you find no errors, refer to Need Help? below.

3. Change the processor mode select switch to the PROG position.

(Failure to do this step now will prevent correct operation.)

Procedure P3 Set Your Industrial Terminal to PLC-2 Mode

1. Press [MODE SELECT]

2. Change the keytop overlay to PLC-2 family.

3. Select PLC-2 mode.

Press 11 on the keyboard

Procedure P4 See How Data Is Stored in the Data Table

1. Move the cursor to the rung containing the read block transfer

instruction (rung 14). The cursor will illuminate the instruction title BLOCK XFER READ.

2. Display the contents of the read block transfer file in hex.

212

Chapter 2

Getting Started with Your ASCII Module

Press [DISPLAY] 1

Results The industrial terminal displays the name and numbers (first 10 characters) that you entered in step 2. For example,

ALLEN 12345 would be displayed as:

POSITION FILE

001 E010

002 0000

003 414C

004 4C45

005 4E20 N

006 3132 1 2

007 3334 3 4

ASCII Equivalent

status word one

status word two

A L

L E

Entering the eleventh character caused the module to transfer the data. Note the space entered between ALLEN and 12345.

The display of status word one (E010) and status word two (0000) indicates normal status of the module.

3. Terminate this display by pressing [CANCEL COMMAND], and

return to ladder diagram.

Need Help?

If your display was all zeros, the data did not transfer. You may have altered the procedure.

Did you enter your program exactly as shown? Did the module’s CHANNEL ACTIVE LED go on? Did you perform Procedure P1 before P2? Did you perform Step 1 in Procedure P2? Did you perform Step 3 in Procedure P2?

213

Chapter 2

Getting Started with Your ASCII Module

If you are still having trouble, refer to “Testing the ASCII Module and Cables,” to verify communication between the ASCII module and the industrial terminal. If you suspect a cable problem, check the 1770-CB cable (Figure 1.4).

Then try again, starting at Procedure P1.

Figure 1.4 Minimum

Connections in the 1770CB Cable

ASCII Module Interface Port

* Protective Ground

Transmitted Data

Received Data

Ground

Industrial Terminal Channel B

Connectors: 25pin DShell Male Connector Cable Kit 1770XXP (each end)

Cable:

Belden 8723 or equivalent

* In cable but not required for ASCII module

11819

Writing Data to Your ASCII Device

214

In this demonstration, you will load data characters into the write block transfer file and observe how they are displayed. You will use the industrial terminal in PLC-2 mode to load data. Then you will change the industrial terminal to alphanumeric mode and observe the transferred data.

Chapter 2

Getting Started with Your ASCII Module

You will use the following procedures where Procedures P1 and P3 are repeated from the section titled Reading Data from Your ASCII Device.

Procedure

ou W

ill

Set your industrial terminal to PLC2 mode

Load data into the write block transfer file

Set your industrial terminal to alphanumeric mode (and observe the transferred data)

Procedure P3 Set Your Industrial Terminal to PLC-2 Mode

NOTE: Skip this procedure if your processor is already in PLC-2 mode.

1. Press [MODE SELECT]

2. Check that the PLC-2 family keytop overlay is in place.

3. Select PLC-2 mode.

Press 11 on the keyboard

The beginning of your ladder diagram program will be displayed.

Procedure P5 Load Data into an Instruction File

1. Check that the processor mode select switch is in the PROG position.

2. Move the cursor to the instruction whose file you want to load

(BLOCK XFER WRITE).

3. Display the file in hex.

Press [DISPLAY] 1

4. Load new data starting in position 003 for a write block transfer

instruction, position 001 for other file instructions. (Positions 001 and 002 are reserved for command words in a write block transfer instruction.)

215

Chapter 2

Getting Started with Your ASCII Module

For example, load the following hex codes that are equivalent to BRADLEY 12345 as follows: (Note the space between BRADLEY and

12345.)

POSITION FILE

003 4252 B R

004 4144 A D

005 4C45

006 5920 Y

007 3132 1 2

008 3334 3 4

009 3500 5

ASCII Equivalent

L E

Check your display of FILE DATA to be sure that you entered all data exactly as shown.

Don’t forget to press [INSERT][

] after entering data in each position.

Use the shift key to enter the hex character C.

Procedure P1 Set Your Industrial Terminal to Alphanumeric Mode

216

1. Insert the alphanumeric keytop overlay.

2. Select alphanumeric mode.

Press [MODE SELECT] 12

3. Set the communication rate to 300 baud.

Press 13 [RETURN]

The module’s CHANNEL ACTIVE LED turns on.

4. Change the processor mode select switch to the RUN/PROG

position.

Chapter 2

Getting Started with Your ASCII Module

Results The following display appears at the upper left corner of the industrial terminal:

BRADLEY 12345

5. Terminate the display and return to ladder diagram. Use the PLC-2

family keytop overlay.

Press [MODE SELECT] 11

Summary

Now that you have demonstrated the transfer of data from your ASCII device to the data table and vice versa, you are ready to use these procedures further. First, read the next chapter, “Choosing Module Features.” It defines key words and concepts. Then in chapter 3, “ASCII Tutorial”, you will use these procedures to demonstrate operating characteristics of your module.

217

Chapter 2

Getting Started with Your ASCII Module

PLC3 Processors

What You Need To Get Started

You will set up a test I/O chassis with a PC processor, power supply, industrial terminal, cables, and your ASCII module. You will need about an hour to complete the procedures in this chapter and about two hours to complete the procedures in chapter 3.

You may want to record your application ladder diagram program before proceeding because you will need to load ASCII logic into a cleared memory for tutorial chapters 1 and 3 in this manual.

Equipment That You Need

You will need the following equipment (Table 1.C) using your existing system and/or spare equipment.

218

Chapter 2

Getting Started with Your ASCII Module

Table 1.C Equipment

PLC3 Main Chassis Main Processor Module I/O ScannerProgrammer Interface Module Memory Module Power Supply

Industrial T PLC3 Keytop Overlay

I/O Chassis Remote I/O Adapter Module ASCII i/O Module

winaxial I/O Interface Cable IT/DH Adapter Cable PLC3 Industrial T Chassis Power Cable I/O Power Cable Terminators

[1] [2]

(PLC3)

Equipment

erminal

erminal Cable

Supplied with the Industrial T Supplied with the PLC3 Main Chassis

erminal

Catalog Number

1775A1

1775L1,L2

1775S4A

1775MR

1775P1

1770T4

1770KDA

1771Al,A2,A4

1771AS

1771DA

1770CD

1770CB 1775CAT 1775CAP

1775CH

1775XT

[1]

[2]

If you use an existing system, place the ASCII module in a chassis on a separate channel. Use a spare scanner module (cat. no. 1775-S4A,-S4B) if necessary.

The ASCII module draws 1.3A from the backplane. If you place the module in a chassis containing other modules, be sure that the total current drain of all modules in the chassis does not exceed the maximum for the backplane and power supply.

219

Chapter 2

Getting Started with Your ASCII Module

How to Connect Your Equipment

Connect your equipment using the appropriate cables (Figure 1.5).

120V AC

1775-P1 Power Supply

1775-CAP Chassis Power Cable

Figure 1.5 Connections

UNIT

(CPU)

RAM

CENTRAL

PROCESSIN

for PLC3 Controller

1775-CAT Industrial Terminal Cable

I/O S

1775-S4A Scanner

PLC-3 Processor Chassis

1771-DA ASCII I/O Module

1771-T4 Industrial Terminal (rear view)

Channel B Change Cables as required

220

1771-CH I/O Power Cable

1770-CD Twinaxial Cable, 10,000 ft. Max. total each I/O Channel

1771-AS Romote I/O Adapter Module

1771-A1, -A2, -A4 I/O Chassis

1772-TC Processor Interface Cable

1770-CB IT/DH Adapter Cable

1. Connect the chassis power cable between the power supply and the

processor chassis.

11820

Chapter 2

Getting Started with Your ASCII Module

2. Connect the I/O power cable between the power supply and the I/O

chassis.

3. Connect the twin axial cable between the I/O scanner in the

processor chassis and the remote I/O adapter module in the I/O chassis (Figure 1.6).

Figure 1.6 Twinaxial

Cable T

erminations

Terminals on I/O Scanner Module

Channel No. 3

Channel No. 1

Line 1

Shield

Line 2

Blue

Shield

Clear

Line 2

Terminator Resistor (Cat. No. 1770-XS or 1770-XT) 150 ohm 0.5 W

1770CD Twinaxial Cable

Terminals on field Wiring Arm of 1770-AS Adapter Module

Blue Shield Clear

Line 1

Shield

Line 2

Line 1

Shield

Line 2

Terminator Resistor (Cat. No. 1770-XT) 150 ohm 0.5 W

Channel No. 4

Channel No. 2

Absence of a terminator resistor can cause block

NOTE:

transfer errors

4. Connect the industrial terminal cable between channel B of the

industrial terminal and the processor chassis.

11821

221

Chapter 2

Getting Started with Your ASCII Module

5. Connect the IT/DH adapter cable between the ASCII module and

Channel B

Periodically you will have to switch the cables that connect to channel B of the industrial terminal.

channel B of the industrial terminal.

You will use the industrial terminal cable (cat. no. 1775-CAT) when

using the industrial terminal in PLC-3 mode and entering or displaying data in the PLC-3 data table.

You will use the IT/DH adapter cable (cat. no. 1770-CB) when using

the industrial terminal in alphanumeric mode as an ASCII device connected to your ASCII module.

Be sure to observe the labels on the cable connectors and connect each

to its designated port.

Also, if the IT/DH adapter cable is too short or not available, make your own. It should not exceed 50 feet (Figure 1.7).

Figure 1.7 Minimum

ASCII Module Interface Port

Connections in the 1770CB Cable

* Protective Ground

Transmitted Data

Received Data

Ground

Industrial Terminal Channel B

Connectors: 25pin DShell Male Connector Cable Kit 1770XXP (each end)

Cable:

Belden 8723 or equivalent

* In cable but not required for ASCII module

222

11819

Chapter 2

Getting Started with Your ASCII Module

Refer to your PLC-3 Programmable Controller Installation and Operation Manual (publication 1775-800) for additional installation information such as switch settings for the adapter module and I/O chassis, and for grounding information.

Checking ASCII Module Configuration

Your module is configured for RS-232-C operation when shipped from the factory. If you suspect that its internal configuration (settings of internal programming plugs) has been altered, you should check module configuration (refer to section titled ”Choosing the Mode of Communication,” in chapter 2). Do this as follows:

1. Remove the covers from the module’s printed circuit board.

2. Locate the programming plugs, and set them according to RS-232-C

without control lines (Figure 2.8).

Entering the Getting Started Program"

Using your industrial terminal, enter the “Getting Started Program” (Figure 1.8) into processor memory. At this point, you do not need to understand how the program works, but you should enter it exactly as shown.

223

Chapter 2

Getting Started with Your ASCII Module

Figure 1.8 Getting

I0001

WO005:0000

WO003:0000

WO003:000015WO002:0000

WO005:000002WO003:0000

Started Program" (PLC3)

RUNG NUMBER RM0

RUNG NUMBER RM1

RUNG NUMBER RM2

RUNG NUMBER RM3

RUNG NUMBER RM4

MOV

MOVE FROM A TO R

A : WO001:0000

0000000000000000

R : WO002:0000

0000000000000000

WO002:0000

WO005:0000

WO002:0000

224

I0001

I000102WO005:0000

WO005:0000

WO005:000004WO003:0000

RUNG NUMBER RM5

RUNG NUMBER RM6

RUNG NUMBER RM7

RUNG NUMBER RM8

RUNG NUMBER RM9

WO005:0000

WO002:0000

Chapter 2

Getting Started with Your ASCII Module

RUNG NUMBER RM10

001

CNTL

WO005:0000

WB004:0000

RUNG NUMBER RM11

BTR BLOCK XFER READ RACK : GROUP :

MODULE : DATA : LENGTH = CNTL :

BTW BLOCK XFER WRITE RACK : GROUP : MODULE : DATA : LENGTH = CNTL :

1=HIGH

FO003:0000

FB004:0000

1=HIGH

FO002:0000

FB004:0000

1. Connect the 1775-CAT cable to channel B of the industrial terminal.

2. Turn on power to the I/O chassis and PLC-3 controller.

3. Turn off the memory protect switch on the front panel of the PLC-3

controller.

4. Select program load mode on the PLC-3 front panel.

Press [SHIFT][LIST] 3 [ENTER]

5. Turn on the industrial terminal. It should automatically display

ladder diagram mode. If not,

Press [SHIFT][MODE]1

6. Enter the following key sequence on the industrial terminal keyboard

before entering your program.

Press[INSERT][SHIFT][RUNG][ENTER]

225

Chapter 2

Getting Started with Your ASCII Module

The displayed power bars will be replaced by I’s at the left and right margins of the screen. The prompt EDITING will blink.

7. Enter your instructions and addresses. Refer to the PLC-3

NOTE: Be sure that you have entered the prefix F (file) in the addresses

of your block transfer read (BTR) and block transfer write (BTW) instructions. Create a (nominal) 64 word file for your BTR and BTW data files as follows:

where the <> symbols are not entered but designate data that you enter. Example file addresses are O3:0 and O2:0.

Programming Manual (publication 1775-801) as needed.

Press CR,<file address>100,Y [ENTER]

8. Assemble your program.

Press ASM,Y[ENTER]

The power bars now become solid lines.

9. Check your program using the consecutive display mode starting

with the first rung.

Press [SHIFT][DISPLAY][ENTER]SR[ENTER]

Use [RUNG

↓] and [RUNG ↑] as needed to move from rung to rung.

Installing Your ASCII Module

Be sure that power to the I/O chassis is turned off when installing (or removing) your ASCII module as follows:

1. Turn off power to the I/O chassis.

226

2. Insert the ASCII module in rack 1, module group 1, slot 1. The

program makes the processor communicate with the ASCII module at that specific location. (If you must use another rack location and are familiar with programming block transfer instructions, change

Chapter 2

Getting Started with Your ASCII Module

the rack, group, and slot number of the module address in the block transfer read and write instructions, accordingly.)

3. Turn on power to the I/O chassis. Three LED indicators on the

ASCII module illuminate momentarily. Their functions are:

FAULT: Normally off. This red LED indicator illuminates when the module detects an internal fault.

BUFFER FULL: Normally off. This yellow LED indicator illuminates when the input buffer becomes full.

CHANNEL ACTIVE: This green LED indicator illuminates when the industrial terminal is on, properly connected to the ASCII module’s interface port, and set for alphanumeric mode.

227

Chapter 2

Getting Started with Your ASCII Module

Reading Data from Your ASCII Device

In this demonstration you will enter data and observe how it is stored in the processor data table. You will use the industrial terminal in alphanumeric mode as an ASCII data terminal when you enter data. Then you will change the industrial terminal to PLC-3 mode and observe the transferred data by displaying the contents of the block transfer read file. You must alternate cables that connect to channel B of the industrial terminal, one cable for alphanumeric mode, the other for PLC-3 mode. You will simulate the action of an input bit through the PLC-3 front panel to enable a write block transfer.

You will use the following procedures.

Procedure

Connect the 1770CB cable, and set your industrial terminal to alphanumeric mode

Enter your data

Connect the 1775CA terminal to PLC3 mode

See how data is stored in the data table

ou W

ill

T cable, and set your industrial

Even if you are familiar with these procedures, read them completely. If you deviate from these procedures, proper operation may not occur.

If you have not already done so, load the “Getting Started Program” (Figure 2.8) into processor memory.

Procedure 1 Set Your Industrial Terminal to Alphanumeric Mode

1. Turn on the industrial terminal.

2. Connect the 1770-CB cable to channel B of the industrial terminal.

3. Select alphanumeric mode.

Press [SHIFT][MODE] 2

The CHANNEL ACTIVE LED on the module illuminates.

228

Chapter 2

Getting Started with Your ASCII Module

4. Set operating parameters:

Communication rate to 300 baud. Press A (as needed) until the

communication rate, as displayed on the screen, reaches 300 baud. Hardware handshaking to ON. Press D DUPLEX to FULL. Press F B and C to any setting. E, and G thru M to OFF. Press [ENTER] to load parameters.

The prompt, ENTERING ALPHANUMERIC TERMINAL MODE, tells you the terminal is ready for your input.

Procedure P2 Enter Your Data

1. Check that the PLC-3 controller is operating in run monitor. Use the

PLC-3 front panel.

Press [SHIFT][LIST] 2 [ENTER]

2. Enter data, such as your first name, followed by a couple of numbers.

Enter 11 characters counting the space between your name and numbers. Select the characters from commonly used data characters (Table 1.D).

Table 1.D Commonly

Used Data Characters

ASCII Hex ASCII Hex ASCII Hex

space 20 A 41 N 4E

0 30 B 42 O 4F

1 31 C 43 P 50

2 32 D 44 Q 51

3 33 E 45 R 52

4 34 F 46 S 53

5 35 G 47 T 54

6 36 H 48 U 55

7 37 I 49 V 56

229

Chapter 2

Getting Started with Your ASCII Module

The industrial terminal displays the characters as you enter them. If characters are not displayed, check the program that you loaded into memory. Check step 3, operating parameters, for errors. If you find no errors, refer to Need Help? below.

Procedure P3 Set Your Industrial Terminal to PLC-3 Mode

ASCII HexASCIIHexASCIIHex

8 38 J 4A W 57

9 39 K 4B X 58

L 4C Y 59

M 4D Z 5A

1. Connect the 1775-CAT cable to channel B.

2. Display your ladder diagram.

Press [SHIFT][MODE]1

Procedure P4 See How Data Is Stored in the Data Table

1. Display the block transfer read file. Enter the address of that file

(O3:0) with the following key sequence.

Press DD,O3:0, [SHIFT]%A [ENTER]

Results The name and numbers (11 characters or more) that you entered are displayed. For example, if you had entered

ASCII 7890123

230

the space between ASCII and 78790123 would count as an entered character, and your display would show 10 characters as follows:

RADIX

= %A START = W

WORD #

00000 E0H11H 00H00H ASCII 789000H00H

0 1 2 3 4 5 6 7

A011:0248

Chapter 2

Getting Started with Your ASCII Module

2. Display the same file in hex.

Press,%H [ENTER]

The following display appears:

RADIX

= %A START = W

WORD #

00000 E011 0000 4153 4349 4920 3738 3930 0000

0 1 2 3 4 5 6 7

A011:0248

3. You can display the file in other number bases by replacing the H in

step 2 with D for decimal, B for binary, or A for ASCII.

Compare the following displays.

Number

Base

ASCII (A)

Hex (H)

Decimal (D)

Display

A S C I I 7 8 9 0 00H00H

41 53 43 49 49 20 37 38 39 30 0000

41 53 43 49 49 20 37 38 39 30 000

Zero V

alue

Results Entering the eleventh character caused the module to transfer the data.

Status word one (E011) and status word two (0000) indicate normal operation of the module. These are shown in display words 0 and 1, respectively.

4. Terminate this display and return to ladder diagram.

Press [SHIFT][MODE]1

Need Help?

If your display was all zeros (00H00H), ASCII display), the data did not transfer. You may have altered the procedure.

Did you enter your program exactly as shown? Did the module’s CHANNEL ACTIVE LED go on? Did the CHANNEL 1 LED on your scanner go on? Did the ACTIVE LED on your adapter go on? Have you configured your PLC-3 controller (LIST function)?

231

Chapter 2

Getting Started with Your ASCII Module

Then try again starting with Procedure P1.

Writing Data to Your ASCII Device

In this demonstration you will load data characters into the write block transfer file and observe how they are displayed by the industrial terminal. You will use the industrial terminal in PLC-3 mode to load data. Then you will change the industrial terminal to alphanumeric mode and observe the transferred data.

The procedures that you will follow are described below.

Procedure

P3 Connect

P5 Load

P1 Connect

the 1775CA

mode

data into the file

the 1770CB cable, and set your industrial terminal to alphanu

mode

meric

Enable the transfer of new data

T cable, and set your industrial terminal to PLC3

ou W

ill



Procedure P3 Set Your Industrial Terminal to PLC-3 Mode

232

NOTE: Skip this procedure if the industrial terminal is already in PLC-3 mode.

1. Connect the 1770-CAT cable to channel B.

2. Set your industrial terminal to PLC-3 mode, and display the

beginning of your ladder diagram program.

Press [SHIFT][MODE]1

Procedure P5 Load Data into a File

1. Place the processor in program load mode using the PLC-3 front

panel.

Chapter 2

Getting Started with Your ASCII Module

Press [SHIFT][LIST]3[ENTER]

2. Display the file that you want to load by entering the address of that

file (O2:0) with the following key sequence.

Press DD,O2:0,[SHIFT]%A[ENTER]

3. Load ASCII data into the file starting with the third word (display

word 2) for block transfer instructions (the first word for file move instructions). The first and second words of a write block transfer instruction are reserved for command words (handshaking). Press [ENTER] and [ ] after loading each word.

For example, if you load the following:

BRADLEY 1234

Your file will appear as

RADIX

= %A START = W

WORD #

00000 60H00H 00H00H BRADLE Y 123 4

0 1 2 3 4 5 6 7

A011:0248

4. Change the display to hex and observe how the equivalent data is

displayed.

Press,[SHIFT]%H[ENTER]

Your file display will change to the following:

RADIX

= %A START = W

WORD #

00000 E011 0000 4252 4144 4C45 5920 3132 3334

0 1 2 3 4 5 6 7

A011:0248

Check the display of data to be sure that you entered all data exactly as shown.

Procedure P1 Set Your Industrial Terminal to Alphanumeric Mode

233

Chapter 2

Getting Started with Your ASCII Module

1. Connect the 1770-CB cable to channel B.

2. Select alphanumeric mode.

3. Check operating parameters:

Press [SHIFT][MODE]2

Communication rate is 300 baud. Hardware handshaking is ON. DUPLEX is FULL. B and C are any setting. E, and G thru M are OFF. Press [ENTER] to load parameters.

The module’s CHANNEL ACTIVE LED turns on.

4. Change the operation of your PC-3 controller to run monitor from

the PLC-3 front panel.

Press [SHIFT][LIST]2[ENTER]

Procedures P6 Enable the Transfer of New Data

1. Set bit I001/02 to enable program logic (the write block transfer

handshaking) using the PLC-3 front panel.

Press [CLEAR][SHIFT]I0[SHIFT][BIT]1[BIT]2

[DISPLAY]

The front panel displays the bit address with an asterisk showing its status, 1 or 0.

234

I000:0001/02*0

2. Set the bit using the PLC-3 front panel.

Press 1 [ENTER]

Results The industrial terminal displays

Chapter 2

Getting Started with Your ASCII Module

BRADLEY 12345

at the upper left corner of the screen.

3. Reset the bit using the PLC-3 front panel.

Press 0 [ENTER]

4. Terminate the display and return to ladder diagram by connecting the

1770-CB cable to channel B, and entering the following keystrokes on the industrial terminal keyboard.

Press [SHIFT][MODE]1

Summary

Now that you have demonstrated how data is transferred from your ASCII device to the data table and vice versa, you are ready to use these procedures further. Next, read “Choosing Module Features,” Chapter 2. It will define key words and concepts. Then, in Chapter 3, “ASCII Tutorial,” you will use these procedures to demonstrate operating characteristics of your module.

235

Chapter

Choosing Module Features

Chapter Objectives

Choosing the Mode of Communication

Because of the many types of ASCII devices available and the variety of possible applications, you must configure your module according to the ASCII device and specific application that you have chosen. To do this, you must make some decisions. We will show you how to configure your module using programming plugs and by setting bits in initialization words.

Following the description of each module feature, we will show you how to record your decision whether to use the feature, and when appropriate, the quantity pertaining to the feature. At the end of this chapter, you will consolidate your decisions on a worksheet. You can use the worksheet to configure your module for your specific ASCII device and application.

This manual uses the following notation when referring to initialization words and bits. There are four initialization words to configure your module: IW1, IW2, IW3, and IW4. Bits within an initialization word are shown in parentheses after the word. For example, bits 10 thru 17 in initialization word three would appear as IW3(10-17).

The ASCII module responds to three modes of communication.

RS-232-C Current Loop, 20mA A-B Long Line

RS232C

Use this mode for communicating up to approximately 50 cable feet between a printer or CRT and the ASCII module. The Electronics Industry Association (EIA) standard RS-232-C sets data and control line voltage levels for serial data communication. Data transmission is negative true logic: -5 to -15Vdc for a logic 1, +5 to +15Vdc for a logic 0. Control line commands are positive true logic: +5 to +15Vdc for enable,

-5 to -15Vdc for inhibit. The standard also specifies a 25-pin connector and defines pin functions. Most systems use only the following pins:

31

Chapter 3

Choosing Module Features

Pin Signal

transmit

data

receive data

request to send

clear to send

ground

Refer to Table 2.A for a detailed listing of RS-232-C pin functions.

Table 2.A RS232C

2 T

Connector Pin Functions

Signal Name

ransmitted Data

Received Data

Request to Send

Clear to Send

Data Set Ready

Signal Ground

Receive Line Signal Detector

EIA

Circuit

BA DTE

BB 1771DA

CA DTE T

CB 1771DA

CC 1771DA

AB 

CF 1771DA

Source Functions

(DCE)

Data T

ransfer to

1771DA (DCE)

Data T

ransfer to DTE

ells the 1771DA data is

transmitted.

ells DTE that data is transmitted. Enabled only if pin 4 is Vdc (of

ells DTE that 1771DA (DCE) is ready

Common ground for all signals thru interface port on 1771DA.

ied to +12V dc

f).

32

Data T

erminal Ready

CD DTE T

ells 1771DA (DCE) that DTE is ready +V dc to send or receive.

. Must be

Current Loop

Use the current loop for communicating up to approximately 500 cable feet between your ASCII device and ASCII module. A current loop has high immunity to errors caused by electrical noise, has no signal attenuation, eliminates ground loops, and is low cost.

A current loop is a loop that carries current (generally 20mA) between electronic equipment by means of a twisted pair of wires. A transmitting device in the loop transmits digital signals by interrupting the current

Chapter 3

Choosing Module Features

flow. A receiving device in the loop senses the interruptions. By convention, a logic 1 corresponds to the presence of loop current; a logic 0 corresponds to the absence of loop current.

A current loop transmitter or receiver can be either of two types: active (source) or passive (sink). An active transmitter supplies current to the loop. Any receivers or other transmitters within that loop must be passive units that accept the supplied loop current. Alternately, an active receiver supplies current to passive transmitters or other passive receivers in the loop.

Current sources that power a current loop vary in complexity. The simplest is a resistor and voltage source. More complex current sources contain active elements or integrated circuits to provide constant current under various power supply and load conditions.

Refer to Table 2.B and Table 2.C for a detailed listing of current loop pin functions.

Pin No.

Table 2.B Current Passive Receive/Passive T

Signal Name

Module T

Module Receiver Circuit

Module T

Module Receiver Circuit Return

Module T Control and Return

ransmitter Circuit

ransmitter Circuit Return

Table 2.C Current Loop Connector Pin Functions Passive Receive/Active T

Signal Name

ransmitter

, Circuit

Loop Connector Pin Functions

ransmit

Source Function

Peripheral or Power Supply Controls current loop, allowing

Peripheral Device

ransmit

Source Function

peripheral device to read data

Completes current loop, allowing transfer of data to 1771DA

Return for module transmitter circuit

Return for module receiver circuit

Controls current loop, allowing peripheral device to read data. Serves as return for transmitter circuit.

Module Receiver Circuit

Module T

Module Receiver Circuit Return

ransmitter Circuit Source

Peripheral Device

1771DA

Completes current loop, allowing transfer of data to 1771DA

Supplies current for current loop interface

Return for module receiver circuit

33

Chapter 3

Choosing Module Features

AB Long Line

Use A-B Long Line for communicating up to 5000 cable feet between an industrial terminal, serving as an ASCII device, and the ASCII module.

Refer to Table 2.D for a detailed listing of A-B Long Line pin functions.

Table 2.D AB

Long Line Connector Pin Functions

Pin No.

2 T

7 T

Signal Name

ransmitted Data

ransmitted Data Return Return for transmitted data

Received Data

Received Data Return

AB Long Line Device

1771DA

Source Function

Data T

ransfer to 1771DA

Data transfer to AB Long Line Device

Return for received data

Selecting the Communication Mode

The communication mode that you choose depends on the cable distance from your ASCII device to your ASCII module, and on characteristics of your ASCII device (Table 2.E).

Table 2.E

of Communication

Mode

If Distance is Less Than

50 feet

And Y

our ASCII Device is a

Data T

erminal Equipment (DTE) and conforms

to RS232C

without control lines with control lines

Then Choose this T

ransmission Mode

RS232C (Figure 2.1)

4wire cable 8wire cable

34

Data Set (modem) and conforms to RS232C

without control lines with control lines

500 feet

5000 feet AB industrial terminal or contains a line driver

DTE and provides a 20mA current source for the transmit line, only

DTE and requires a 20mA external current source for its transmit line

DTE and provides 20mA current sources for transmit and receive lines

receiver for AB long line operation.

RS232C (Figure 2.2)

4wire cable 8wire cable

Current Loop (Figure 2.3) The module powers its own transmit line.

Current Loop (Figure 2.4) Y

ou add the power supply for the DTE.

Current Loop (Figure 2.5) The module operates in passive transmit.

AB Long Line (Figure 2.6)

Chapter 3

Choosing Module Features

The functions of the cable conductors (Figure 2.1 thru Figure 2.7) are referenced to your ASCII device, not to your ASCII module.

Figure 2.1 RS232C

Connections (50 ft. max): Data T

erminal to Data Set

(Refer to specifications in Appendix D)

Device

Data Terminal Equipment (DTE)

Drain Wire (Shield)

Transmit

Receive

Transmitted Data (BA)

Signal Ground (AB)

Received Data (BB)

Request to Send (CA)

ASCII Module

Data Set (DCE)

To I/O Chassis Ground

Receive

Transmit

Belden 8723 or Equiv.

Belden 8778 or Equiv.

Control Lines

NOTE: (AB) thru (CD) refer to RS232C circuit labels.

Clear to Send (CB)

Data Set Ready (CC)

Received Line Signal Detector

Data Terminal Ready

1 Tied to +12Vdc

Solder

an external ground wire (14 ga.) to the drain wire at the cable connector

Connect it to the I/O chassis ground lug. Ground the shield at this end only

11822

35

Chapter 3

Choosing Module Features

Receive

Transmit

Device

Data Set (DCE)

Figure 2.2 RS232C

Connections (50 ft. max): Data Set to Data Set

(Refer to specifications in Appendix D)

Drain Wire (Shield)

Received Data (BB)

Signal Ground (AB)

Transmitted Data (BA)

Request to Send (CA)

ASCII Module

(DCE)

To I/O Chassis Ground

Receive

Transmit

Belden 8723 or Equiv.

Belden 8778 or Equiv.

Control Lines

Clear to Send (CB)

Data Set Ready (CC)

Received Line Signal Detector

Data Terminal Ready

1 Tied to +12Vdc

Solder

an external ground wire (14 ga.) to the drain wire at the cable connector

Connect it to the I/O chassis ground lug. Ground the shield at this end only

NOTE: (AB) thru (CD) refer to RS232C circuit labels.

11822

36

Chapter 3

Choosing Module Features

When configured for current loop and you use terminals 13 and 11 for transmit, your ASCII module powers its own transmit loop (Figure 2.3 and Figure 2.4). Your module can accept an active receive current loop powered by the ASCII device. In this case, module operation is passive transmit and you use module terminals 11 and 18 (Figure 2.5).

Figure 2.3

Loop Connections (500 ft. Max): Device is Active T

Current (Refer to specifications in Appendix D)

ransmit, Passive Receive

ASCII ModuleDevice

Transmit with Current Source

Passive Receive

Drain Wire (Shield)

Transmitted Data

Return

Received Data

Return

an external ground wire (14 ga.) to the drain wire at the cable connector

Solder Connect it to the I/O chassis ground lug. Ground the shield at this end only

To I/O Chassis Ground

(+)

Passive Receive

(-)

(+)

Transmit with Current Source

(-)

11823

Belden 8723 or Equiv.

37

Chapter 3

Choosing Module Features

Figure 2.4

Loop Connections (500 ft. max): Device is Passive T

Current (Refer to specifications in Appendix D)

ransmit, Passive Receive

ASCII ModuleDevice

Passive Transmit

Passive Receive

Drain Wire (Shield)

Transmitted Data

4-20mA mark state

Power

Supply

Received Data

Return

Solder

an external ground wire (14 ga.) to the drain wire at the cable connector

Connect it to the I/O chassis ground lug. Ground the shield at this end only

Figure 2.5

Loop Connections (500 ft max.): Device is Active T

Current (Refer to specifications in Appendix D)

Drain Wire (Shield)

Return

ASCII ModuleDevice

To I/O Chassis Ground

(+)

Passive

Receive

(-)

(+)

Transmit with

Current Source

(-)

ransmit, Active Receive

To I/O Chassis Ground

Belden 8723

or Equiv.

11824

38

Transmitted Data

Transmit with Current Source

Return

Received Data

Receive with Current Source

Solder

an external ground wire (14 ga.) to the drain wire at the cable connector

Connect it to the I/O chassis ground lug. Ground the shield at this end only

Return

NOTE: Device and its power supply must float in respect to the module for passive transmit.

(+)

Passive Receive

(-)

(+)

Belden 8723

or Equiv.

Passive Transmit

(-)

11825

Chapter 3

Choosing Module Features

Use a 25-pin male D-shell connector such as Amp DB-25P for your cable connections to the ASCII module. Terminate the shield to pin 1 at the module end only.

Figure 2.6 AB

Long Line Connections (5000 ft max)

Receive

Channel B

Drain Wire (Shield)

18 25

Solder

an external ground wire (14 ga.) to the drain wire at the cable connector

Connect it to the I/O chassis ground lug. Ground the shield at this end only

Transmitted Data

Return

Received Data

Return

ASCII ModuleIndustrial Terminal

Figure 2.7 RS232C

Simplex W

rite Connections

(Refer to Specifications in Appendix D)

11826

To I/O Chassis Ground

Receive

Transmit

Belden 8723 or Equiv.

ASCII ModuleDevice

(DTE)

Drain Wire (Shield)

7 7

Receive Transmit

3 3

Belden 8723

or Equiv.

[1]

Solder

an external ground wire (14 ga.) to the drain wire at the cable connector

Connect it to the I/O chassis ground lug. Ground the shield at this end only

NOTE: Jumper pin 2 to pin 18 at the module end of the cable (special case).

Signal Ground (AB)

Received Data (BB)

(DCE)

To I/O Chassis Ground

11827

[1]

39

Chapter 3

Choosing Module Features

Setting the Module's Programming Plugs

Implement your choice of cable configuration by setting programming plugs inside the module. Remove the module’s left-hand cover plate (the one without the labels). Locate and adjust the programming plugs according to Figure 2.8.

NOTE: The locations of programming plug sockets (Figure 2.8) are labeled El thru E16 on the printed circuit board. The settings of programming plugs are defined as follows:

IN refers to the plug jumpering the pair of pins at the designated location.

1-2 or 2-3 refers to the pins on which you insert the plug. Pins 1 and 3 are labeled on the circuit board next to the pins.

OUT refers to removing the plug or inserting it on only one pin (electrically floating). You can store up to four plugs in the area labeled JUMPER STORAGE at the right-hand side of the board.

SPECIAL CASE When operating an ASCII device in RS-232-C simplex write mode without a transmit line from the ASCII device (Figure 2.7), jumper pin 2 to pin 18 at the cable connector (module end of cable) and insert a programming plug in location E16 on the ASCII module.

Re-assemble the module after you have finished setting and/or checking the programming plugs.

310

Chapter 3

Choosing Module Features

Figure 2.8 Programming

Plug Locations and Settings

Jumper Storage

E4 E3

E8 E7

E12

E16

E15

E14

E11

E10

E13

Bottom of Module

RS-232-C

Programming

Plug

Location

E-1 E-2 E-3 E-4 E-5 E-6 E-7 E-8

E-9 E-10 E-11 E-12 E-13 E-14 E-15

[2]

E-16

[1]

3-prong connector:

[2]

See Special Case, Choosing the Mode of Communication"

[3]

Remove E4 when initializing the module (IW 1 B05, B06, B07) in half-duplex mode

Without Control

Lines

[1]

1-2 Out

[3]

In In

In Out Out Out 1-2 Out

In Out

12 place programming plug toward pin 1 as labeled on the circuit board 23 place programming plug toward pin 3 as labeled on the circuit board

With

Control

1-2

Out Out

In Out Out Out

1-2

Out

In Out

Current

Loop

[1]

2-3

[3] [3]

Out

In In

In 1-2 2-3 Out

In Out Out Out

A-B

Long

Line

Operation

1-2 Out

Out

In 1-2 2-3

In Out Out Out Out

311

Chapter 3

Choosing Module Features

Setting and Recording Initialization Words

The remaining features are configured by using initialization words. These words are write block transferred to the module at power-up or upon command. You will record your selections of module features by writing codes (0 or 1) for corresponding initialization bits. You can do this with either of the initialization word forms at the end of this chapter. Use one form for data mode operation of the module, the other form for report generation mode of operation. These modes of operation are described next in this chapter. You can also record your selections in the space provided in the text that describes each module feature. Then, at the end of the chapter, you will be asked to rewrite the codes onto the appropriate initialization word form. You will use this information in chapter 4 when you demonstrate module features.

312

Chapter 3

Choosing Module Features

Choosing the Mode of Module Operation, IW1(0204)

The mode of module operation that you choose depends on the application and type of ASCII device. Typically, use data mode when you are reading data from an ASCII device, such as a bar code reader. Use report generation mode when you are writing messages to an ASCII data terminal (Table 2.F).

Table 2.F

of Module Operation

Mode

Use When

Data Mode

Report Generation Mode

All

of your data is converted by the ASCII module and stored in the data table as a single data sions:

2 ASCII characters per word 1 ASCII character per word 3 BCD characters per word 4 BCD characters per word 4 Hex characters per word

String length is from 1 to 62 characters

ou want to select right to left justified margins and/or data

You want to mix ASCII characters with BCD values. In addition to the

ASCII characters per word that your module uses in report generation

2 mode,

you must choose one of the following types of data conversion:

3 BCD characters per word 4 BCD characters per word

type using any one of the following data conver



String length is from 1 to 999 characters

Your

margin is left justified for ASCII data but right justified for BCD val

within the ASCII data

ues

Select data mode using code 000, or report generation mode using code

001. Record your selection in IW1(02-04) using the initialization word form (found at the end of this chapter) or the boxes below.

Mode of Operation

IW1

04 03



313

Chapter 3

Choosing Module Features

Choosing Data Conversion, IW2(1416)

Data conversion refers to the number and type of characteers that you store in a data table. word. The selections of data conversion from which you choose depend on the mode of module operation (Table 2.G).

Table 2.G Data

Conversion

When In

Data mode, you must select one type of data conversion (quantity and type of characters per word). T must reinitialize the module.

Report generation mode, your text is 2 ASCII characters per word. You must select either 3 BCD or 4 BCD characters per word for your BCD values within your text.

o change data conversion, you

Select One

2 ASCII/word 3 BCD/word 4 BCD/word 1 ASCII/word 4 Hex/word

3 BCD/word 4 BCD/word

Using Code

000 001 010 011 100

001 010

Record your selection based on your choice of module operation by writing the code in IW2(14-16) using the form (found at the end of this chapter) or the boxes below.

Data Conversion

IW2

16 15

Using BCD Delimiters (Report Generation Mode, Only), IW4(1016)

314

A BCD delimiter is a character that you place before and after BCD values. It tells the ASCII module to interpret the values as BCD, not as ASCII for conversion.

In report generation mode when using BCD values with ASCII data characters, you must separate BCD values by means of a delimiter. For example, if you want to use the BCD value of 297 in a message and you have selected the asterisk (0101010 in binary or 2A in hex) as the BCD delimiter, you would place the asterisk before and after the BCD value, *297*. Otherwise, the 7-bit ASCII equivalent of BCD 297 would be transferred as unwanted characters.

Chapter 3

Choosing Module Features

Select the BCD delimiter from the following hex characters:: 0A-0F, 1A-1F, 2A-2F, 3A-3F, 4A-4F, 5A-5F, 6A-6F, or 7A-7F. Do not use:

Any character that otherwise would appear in the message The end-of-string delimiter that you will select later

ASCII characters and their codes are listed in tables in appendix C.

Record your selection by writing either the 7-bit binary code, or the 2-digit hex code for the BCD delimiter in IW4(10-16) using the form (found at the end of this chapter) or the boxes below.

BCD Delimiter

Justifying Margins, IW3(03)

IW4

17161514131211

NOTE: The module defaults to the colon (:) as the BCD delimiter if you do not use initialization word four (IW4). However, if you use IW4, you must enter a BCD delimiter.

Margin justification refers to the manner in which data is displayed by your ASCII device or stored in the data table (Table 2.H).

Margin justification is particularly evident when the number of data characters transferred is less than maximum.

Your choice of margin justification depends on the mode of module operation (Table 2.I).

315

Chapter 3

Choosing Module Features

Table 2.H

Justification

Margin

Left

Right

When

Justified

Each New Line Is Displayed

with the Same

Left margin Example: T

ext is left justified.

Example: Dollar values are right

Right margin

justified

and Data Is Stored in the Data

able by Placing

The first character in the upper byte of the lowest word address. Blanks or zeros fill the higher word addresses. Example: PLC2 Family

ABCD EF00 0000

Example: PLC3 Family A B C D E F 0 0 0 0 0 0

The last character in the lower byte of the highest word address. Blanks or zeros fill the lower word addresses. Example: PLC2 Family

0000 00AB CDEF

Example: PLC3 Family 0 0 0 0 0 0 A B C D E F

When

Module

Mode of

Operation Is

Data Mode

Report Generation Mode

Table 2.I Margin Justification/Mode of Operation

our Justification Is

Either left or right (you select)

ASCII data is left justified. BCD values, contained in the string of ASCII data, are right justified.

Record your selection based on your choice of module operation. If you choose data mode, choose either left justification IW3(03) =1 or right justification IW3(03)=0. Record your selection by writing a 1 or 0 in IW3(03) using the form (found at the end of this chapter) or the box pn the next page.

316

Chapter 3

Choosing Module Features

If you choose report generation mode, the module ignores this bit.

Margin Justification

Using the EndofString Delimiter, IW3(1016)

IW3

When the module encounters the end-of-string delimiter in data received from the ASCII device, the module allows the read block transfer of data to the processor. If your ASCII device generates an end-of-string delimiter, use that delimiter. (Refer to the specifications of your device.)

When you use the carriage return as the end-of-string delimiter and the data terminal encounters the end-of-string delimiter, the print head or the cursor of the data terminal returns to the left margin. When using a data terminal, select any ASCII character as the end-of-string delimiter, except the same character as the BCD delimiter. You will get an initialization error and the module will not operate.

In most applications, you will select an end-of-string delimiter. If you do not select an end-of-string delimiter, the module will default to the null (CTRL 0) as the end-of-string delimiter.

Refer to tables in appendix C.5 for the complete list of ASCII characters and their codes.

Sending EndofString Delimiter to Processor (Report Generation Mode, Only), IW3(04)

In report generation mode, you may want to send the end-of-string delimiter code to the processor. You would do this if you want to display single-line messages, and your program uses the carriage return as the end-of string delimiter. You may also want line feed with each carriage return. In this kind of report generation application, you would send the end-of-string delimiter to the processor by setting IW3(04)=1. You would enable line feed on carriage return by setting IW3(05)=1.

317

Chapter 3

Choosing Module Features

Record the 7-bit ASCII code in binary or hex for the end-of-string delimiter in IW3(10-16) using the form (found at the end of this chapter) or the boxes on the next page.

End-of-String Delimiter

Setting String Length, IW2(0013)

IW4

17161514131211

String length is the maximum number of characters that your ASCII module can transfer as a unit from the ASCII device to the processor data table. You set the string length to match that of your ASCII device (data mode), or according to your message requirements (report generation mode) up to the maximum that the module can handle. The maximum number of characters that your ASCII module can handle as a string depends on the module’s mode of operation. In data mode, the module can handle a string of up to 62 characters per block transfer. In report generation mode, the module can handle a string of up to 999 characters, transferred over several block transfers.

The string of characters sent from the device to the module can be fixed or varied in length. Refer to the specifications of your ASCII device. Some ASCII devices generate the same string length for each transfer by adding fill characters, described later, when the amount of data in each transfer varies. The device adds fill characters and an end-of-string delimiter at the end of each message (Table 2.J).

318

Table 2.J

Length

String

If Your ASCII Device

Chapter 3

Choosing Module Features

ou Determine Maximum

String Length By

Automatically places the endofstring delimiter to separate data such as bar codes

Is a data terminal Setting the string length to the

Setting the module' the (longest) length that the ASCII device can transmit (module in data mode)

longest message or line, and entering the endofstring delimiter at the end of each message or line (report generation mode)

s string length to

You will use the string length to determine the block length of the read block transfer instruction and the size of the data table file that receives the string. Refer to section titled Determining Block Transfer Length, P. 2-20, and to section titled Choosing Single or Multiple Transfers IW2(17) P. 2-25 for additional information.

If the string length from the ASCII device exceeds the string length that you set for the module, the next character (beyond the set string length) received in the module’s input buffer causes the module to transfer the string. That character and any additional characters remain in the input buffer until the next transfer.

Set the string length equal to the longest string of characters that your ASCII device can generate in your application. Record the string length in IW2(11-13) by writing the BCD value of the string length using the form (found at the end of this chapter) or the boxes below.

ASCII Characters/String

IW2

13 12

11 10 07 06

05 04 03 02 01 00

319

Chapter 3

Choosing Module Features

Determining Block Transfer Length

Initialization WRITE Block

17 16 15 14 13 12 11 10 07 06 05 04 03 02 01 00

Command Word No. 1

Command Word No. 2 Initialize Data Word No. 1 Initialize Data Word No. 2 Initialize Data Word No. 3 Initialize Data Word No. 4

The highest number of words that you can transfer in one block transfer is

64. You must include two command words in each write block transfer and two status words in each read block transfer in addition to your data words. You can also transfer up to four initialization words (Figure 3.9).

Figure 2.9

Lengths for Read and W

Block

WRITE Block

17 16 15 14 13 12 11 10 07 06 05 04 03 02 01 00

Command Word No. 1 Command Word No. 2

64 Words, max. Data

rite Block T

ransfers

READ Block

17 16 15 14 13 12 11 10 07 06 05 04 03 02 01 00

Status Word No. 1 Status Word No. 2

64 Words, max. Data

320

The longest data string read from the ASCII device determines the block length of the read block transfer instruction. In the PLC-2 family, the read and write block lengths must be equal to ensure correct operation. For PLC-3 processors, the block lengths can be different.

Chapter 3

Choosing Module Features

Compute block length by dividing the number of data characters in the longest string length by the type of data storage, i.e. 1, 2, 3, or 4 characters per word. For example, a string of 80 data characters having 2 ASCII characters per word, data storage would require a block transfer block length of 42 words. Don’t forget to add two status words or two command words.

80/2 + 2 = 40 + 2 = 42

A string of 37 data characters having 3 BCD characters per word of data storage would require a block length of 15 words. Round remainders to the next highest whole number.

37/3 + 2 = 12 1/3 + 2 = 13 + 2 = 15

Removing the Fill Character (Data Mode, Only), IW4(1016)

When you have a mix of BCD and ASCII data characters in report generation mode, allow space for right justification of BCD values within the data string. Overestimate your read block transfer block length. Observe how the transferred data is stored, then reduce the block length if possible.

Some ASCII devices add fill characters such as spaces, nulls, or some ASCII symbol when sending data to the module. These devices have the capability to vary the number of data characters, and to add fill characters so that the sum of data and fill characters is always the same for each transfer.

The module removes the fill character that you select whenever the module encounters it in the data received from the device. For example, suppose the device inserted a dash as the fill character (2D in hex) after data characters, and varied the number of data characters sent to the module. Then the device generated the following two transfers:

31 33 32 35 36 39 38 2D 2D 2D 2D first transfer 37 35 39 31 2D 2D 2D 2D 2D 2D 2D second transfer

321

Chapter 3

Choosing Module Features

The module would remove the fill character and store the data as follows (assume right justified data, a string length of 11, and two ASCII characters per word).

First

Transfer

2020 2020

2031 2020

3332 2020

3536 3735

3938 3931

Second

Transfer

The module removed the fill characters inserted by the device (2D hex), right justified the data, and added its own fill character (20 hex).

Select any ASCII character as the fill character that the module will remove except:

- Any character that otherwise would be included in the data

- The end-of-string delimiter that you chose in section titled Using the End-of-String Delimiter, IW3(10-16), P. 2-17.

ASCII characters and their codes are listed in tables in appendix A.

322

Record your selection by writing the 7-bit ASCII code in binary or hex in IW4(10-16) for the fill character to be removed. Use the form (found at the end of this chapter) or the boxes below.

Removed Fill Character

IW4

17 16

14 13

Your ASCII Module Inserts Fill Characters

The module has two non-selectable internal fill characters, the space (20 hex) that is displayed at a data terminal as a space and the null (00 hex) that is not displayed. When justifying data, the module inserts fill characters according to the data conversion that you have selected. It

Chapter 3

Choosing Module Features

inserts a space (20 hex) for one ASCII or two ASCII characters per word conversion, or it inserts a zero (00 hex) for BCD and hex data conversion.

The module also adds a fill character to justified BCD data. The fill character that it inserts is a zero for each missing digit. The module also inserts zeros leading a BCD number, if necessary, to align the BCD number on a word boundary (right justified).

Removing Header and Trailing Characters, IW4(0003, 0407)

Some ASCII devices, such as bar code readers, generate a series of characters that precede and/or trail data characters. Often, some or all of these leading or trailing characters contain no information of use to the PC processor. If your ASCII device generates header and/or trailing characters that are not used, you can remove them. You can remove up to 15 characters of either type (Figure 2.10). If you do not want to remove any, set the corresponding bits to zero.

Figure 2.10 Removing

Header and Trailing Characters

Header Characters

Remove up to 15 header and/or trailing characters

Data String

Data Characters

Trailing Characters

11829

Record the number of trailing characters in IW4(04-07) and the number of header characters in IW4(00-03) that you want to remove. Write the binary code for the numbers on the form (found at the end of this chapter) or in the boxes below.

Removed Trailing Characters

323

IW4

Removed Trailing Characters

07 06

Chapter 3

Choosing Module Features

Choosing I/O Buffer Size, IW3(0002)

Your ASCII module has a 1536 word (3072 byte) buffer for I/O data. The percentage of buffer memory that you choose for input and output depends on the operation of your ASCII device, and on relative transmission rates into and out of the ASCII module’s I/O buffer. You should proportion the size of your input and output buffers for maximum storage (Table 2.K) so that the buffer does not fill and result in loss of data, a condition known as spillover.

Table 2.K

Buffer Size

I/O

When Your ASCII Device

Is bidirectional

Can only generate input data to the ASCII module

Is bidrectional but most data is read from the ASCII device

Is bidirectional but most data is written to your ASCII device

And When

ou want to divide buf

ou want to maximize the number of characters that the

module'

s input buf

Same as block above

ou want to maximize the number of characters that the

module'

s output buf

fer space equally

fer can store before spilling data

Select

50% Input

50% Output

100% Input

75% Input

25% Output

25% Input

75% Output

Using

Code

000

001

010

011

Can only display data

Same as block above

100% Output

Record the percentage of input to output that you want the buffer to have by writing the corresponding 3-digit code in IW3(00-02). Use the form (found at the end of this chapter) or the boxes below.

I/O Buffer Size

IW3

02 01

100

324

Chapter 3

Choosing Module Features

Choosing Transmission Mode, IW1(0507)

If Y

our

ASCII Device Is

Full Duplex

Simplex Read

Simplex W

Half Duplex

rite

That your ASCII device displays data sent to the ASCII module

That no data is displayed

Only the transmission of data from your ASCII device

Only the display of data received by your ASCII device

That your ASCII device displays data sent to the ASCII module

That no data is displayed

The transmission mode that you choose is determined by the specifications of your ASCII device and the requirements of your application (Table 2.L).

Table 2.L

of T

Mode

And Your Application Requires

ransmission

Then Select

Full Duplex with Echo

Full Duplex without Echo

Simplex Read or Full Duplex

Simplex W Duplex

Half Duplex with Echo

Half Duplex without Echo

rite or Full

Using Code

000

001

010

011

100

101

Choosing Single or Multiple Transfers, IW2(17)

Record the mode of transmission selection by writing the 3-digit code in IW1(05-07). Use the form (found at the end of this chapter) or the boxes below.

Mode Transmission

IW1

07 06

Choose single transfer when you want the module to send a single string to the processor in each block transfer, or when the string is long enough to require more than one block transfer.

Choose multiple transfers when your ASCII device transmits short strings (31 characters per string or less) at a high rate of transmission. Then the module will include more than one string in each block transfer. The highest number of strings that you can transfer in one block transfer is the number of complete strings that the module can load into 62 (or fewer) block transfer words.

325

Chapter 3

Choosing Module Features

Record your choice by writing a 0 (single transfer) or 1 (multiple transfer) in IW2(17). Use the form (found at the end of this chapter) or the boxes below.

Single or Multiple Transfers

Selecting Delay for Carriage Return, IW3(0607)

IW2

When using an unbuffered data terminal, select a time for the ASCII module to delay outputting data while the mechanical carriage return is operating. Your selections are:

Delay Time (ms)

0 00

50 01

100 10

200 11

Code

Record your selection by writing the code in IW3(07,06) using the form (found at the end of this chapter) or the boxes below.

Delay for Carriage Return

Setting Remaining Bits in IW1(1017)

326

IW3

07 06

Set the remaining bits in initialization word one according to the specifications of your ASCII device.

Chapter 3

Choosing Module Features

Communication Rate

Match the communication rate of your ASCII module with that of your ASCII device. Set bits IW1(10-12) accordingly. Your selections are:

Communication

Rate

300

baud

600 baud

1200 baud

2400 baud

4800 baud

9600 baud

10 baud

Code

000

001

010

011

100

101

110

Number of Data Bits

Your ASCII device generates either seven or eight data bits per character (Figure 2.11). The ASCII module neither stores nor outputs the eighth bit, but must know if it is there. Use the default value (eight bit data) if this information is not available. Set bit IW1(113) accordingly.

Figure 2.11

Byte Storage in Module

Data

Bit 1 Bit 2 Bit 3 Bit 4 Bit 5 Bit 6 Bit 7

Eighth bit is ignored by the ASCII Module

Bit 8

11830

327

Chapter 3

Choosing Module Features

Parity

Your ASCII device generates either odd, even, or no parity bit with each character (Figure 2.12). Use the default value (no parity) if this information is not available. Set bits IW1(14,15) accordingly.

Figure 2.12

Data on RS232C Line

Serial

Bit 1 Bit 2 Bit 3 Bit 4 Bit 5 Bit 6 Bit 7 Bit 8

or Marker

Start BitLast Stop Bit

Optional

Parity Bit, Optional

Stop Bits

Optional

11831

Number of Stop Bits

Your ASCII device generates either one or two stop bits (Figure 2.12). Use the default value (one stop bit) if this information is not available. Set bit IW1(16) accordingly.

ACK/NAK

Some ASCII devices require an ACK/NAK response from the ASCII module. An acknowledgment of no errors found in a string (ACK) or acknowledgment of an error found in the string (NAK) is required by some ASCII devices in order to complete its transmission. Other ASCII devices do not require acknowledgment.

328

The ASCII module does not require an ACK/NAK to complete its transmission. Most ASCII devices do not require transmission acknowledgment. Set bit IW1(17) accordingly.

Chapter 3

Choosing Module Features

Record features that apply to your ASCII device by writing a 0 or 1 in corresponding bits IW1(10-17) using the form (found at the end of this chapter) or the boxes below.

Bit Number

Selecting the Number of Initialization Words, IW1(0001)

IW1

17 16

14 13

Communciation rate code

Number of Data Bits: 0=8, 1=7 Parity: 0=Odd, 1=Even Parity Enable: 0=No, 1=Yes Stop Bits: 0=one, 1=two

ACK/NAK: 0=No, 1=Yes

Select the number of initialization words for transfer to the ASCII module after deciding which of the module features are required for your ASCII device and application. You select module features by setting bits in four initialization words. Set the number of initialization words equal to the highest numbered initialization word used. For example, if you need a feature found in word four, you must select all four initialization words.

Number

of W

ords Code

ord 1

ords l and 2

ords 1, 2, and 3

ords 1, 2, 3, and 4

Review your selections of module features. Record the code for the number of initialization words that you need in IW1(00-01). Use the form (found at the end of this chapter) or the boxes below.

Number of

Initialization

Words

IW1

01 00

329

Chapter 3

Choosing Module Features

Recording Bit Settings in Initialization Words

The next two pages are forms for recording bit settings in the four initialization words. Form 5l75 is for data mode operation of your module; form 5176 for report generation mode. Copy these forms and use them to record your selections of module features.

You will use the information that you record on these forms in chapter 3 to set bits in initialization words and to demonstrate the features that you have selected.

330

Form 5175 Initialization Words for Data Mode

Chapter 3

Choosing Module Features

IW1

Record Your Selections

IW2

Record Your Selections

17 16 15 14 13 12 11 10 07 06 05 04 03 02 01 00

ACK NAK

0 = *

Yes

Hex Equivalent

Rate Data Conversion Number of ASCII Characters Per String

0 = *

Single

Multi.

Stop

Parity

Bits

Enable

0 = 1*

Stop

1 =

1 = 2

Stop

Bits

17 16 15 14 13 12 11 10 07 06 05 04 03 02 01 00

1 =

0 = *

Bit

0 0 0 = 2 ASCII

0 0 1 = 3 BCD 0 1 0 = 4 BCD

0 1 1 = 1 ASCII

1 0 0 = 4 Hex

1 =

Yes

Parity

Odd, even

0 = *

Odd

1 =

Even

No. of

bits

0 = 8*

Bit

Data

1 = 7

Bit

Data

Communication

Rate

000 = 300 Baud* 001 = 600 Baud 010 = 1200 Baud 011 = 2400 Baud 100 = 4800 Baud 101 = 9600 Baud 110 = 110 Baud 111 = 110 Baud

BCD Digit 2 BCD Digit 1 BCD Digit 0

000=Full Duplex w/Echo* 001=Full Duplex w/o Echo

010=Simplex Read 011=Simplex Write

100=Half Duplex w/Echo 101=Half Duplex w/o Echo

Mode of

Transmission

Default = 10, Maximum = 62

Mode of

Operation

0 0 0

Number of

Initialization

Words

00 = Word 1*

01 = Words

1 & 2

10 = Words

1, 2 & 3

11 = Words

1, 2, 3 & 4

IW3

Record Your Selections

IW4

Record Your Selections

Hex Equivalent

17 16 15 14 13 12 11 10 07 06 05 04 03 02 01 00

Enable

EOS

Del.

0 = *

Yes

1 = No

0 0 0 0

Hex Equivalent

17 16 15 14 13 12 11 10 07 06 05 04 03 02 01 00

0 0 0 0

Hex Equivalent

EndofString Delimiter

(EOS Del.)

Null * (CTRL 0)

Fill Character Removed Number of Trailing Characters

( : ) *

Must not be same as IW3 (10  16)

Delay for CR LF ifCRSend

00 = 0 ms*

01 = 50 ms 10 = 100 ms 11 = 200 ms

Removed

0 *  15

binary

0 = *

1 =

Yes

EOS

Del

0 = *

1 =

Yes

Data Just.

0 = *

Right

1 =

Left

Number of Header Characters

I/O Buffer Split

Input/Output

000 = 50 / 50 *

001 = 100 / 0 010 = 75 / 25 011 = 25 / 75 100 = 0 / 100

Removed

0 *  15

binary

* = default value

11833

331

Chapter 3

Choosing Module Features

Form 5176 Initialization Words for Report Generation Mode

IW1

Record Your Selections

IW2

Record Your Selections

17 16 15 14 13 12 11 10 07 06 05 04 03 02 01 00

ACK NAK

0 = *

Yes

Hex Equivalent

Rate Data Conversion Number of ASCII Characters Per String

0 = *

Single

Multi.

Stop

Parity

Bits

Enable

0 = 1*

Stop

1 =

1 = 2

Stop

Bits

17 16 15 14 13 12 11 10 07 06 05 04 03 02 01 00

1 =

0 = *

Bit

0 0 1 = 3 BCD 0 1 0 = 4 BCD

1 =

Yes

Parity

Odd, even

0 = *

Odd

1 =

Even

No. of

bits

0 = 8*

Bit

Data

1 = 7

Bit

Data

Communication

Rate

000 = 300 Baud* 001 = 600 Baud 010 = 1200 Baud 011 = 2400 Baud 100 = 4800 Baud 101 = 9600 Baud 110 = 110 Baud 111 = 110 Baud

BCD Digit 2 BCD Digit 1 BCD Digit 0

000 = Full Duplex w/Echo* 001 = Full Duplex w/o Echo

010 = Simplex Read 011 = Simplex Write

100 = Half Duplex w/Echo 101 = Half Duplex w/o Echo

Mode of

Transmission

Default = 124, Maximum = 999

Mode of

Operation

0 0 0

Number of

Initialization

Words

00 = Word 1*

01 = Words

1 & 2

10 = Words

1, 2 & 3

11 = Words

1, 2, 3 & 4

IW3

Record Your Selections

IW4

Record Your Selections

Hex Equivalent

332

17 16 15 14 13 12 11 10 07 06 05 04 03 02 01 00

Enable

EOS

Del.

0 = *

Yes

1 = No

0 0 0 0

17 16 15 14 13 12 11 10 07 06 05 04 03 02 01 00

0 0 0 0

EndofString Delimiter

(EOS Del.)

Null * (CTRL 0)

Fill Character Removed Number of Trailing Characters

( : ) *

Must not be same as IW3 (10  16)

Delay for CR LF ifCRSend

00 = 0 ms*

01 = 50 ms 10 = 100 ms 11 = 200 ms

Removed

0 *  15

binary

0 = *

1 =

Yes

EOS

Del

0 = *

1 =

Yes

Data Just.

0 = *

Right

1 =

Left

Number of Header Characters

I/O Buffer Split

Input/Output

000 = 50 / 50 *

001 = 100 / 0 010 = 25 / 75 011 = 25 / 75 100 = 0 / 100

Removed

0 *  15

binary

* = default value

11833

ASCII I/O Module Tutorial

Chapter

Chapter Objectives

You will use three general procedures in this tutorial.

Setting bits in your initialization words Reading data from your industrial terminal Writing data to your industrial terminal

You will observe the results of setting bits in your initialization words by reading data from or writing data to your ASCII device. The procedures for reading and writing data were covered in chapter 1. The procedure for setting bits in your initialization words is covered after you have added initialization logic to your program.

As in chapter 1, this chapter is divided into two parts. One is for PLC-2 family processors, the other is for the PLC-3 processor. Proceed to the part that pertains to your processor.

41

Chapter 4

ASCII I/O Module Tutorial

PLC2 Family Processors

Adding Initialization Rungs

020

252

020

062

020

063

327

000

063

You must add initialization rungs to your “Getting Started Program”. Place the processor mode select switch in the PROG position and insert the additional rungs exactly as shown (Figure 3.1).

To insert one or more rungs into your program, place the cursor on the output instruction in the previous rung. Press [INSERT][RUNG], then enter the instructions for one rung. You must press [INSERT][RUNG] before inserting each new rung.

Figure 3.1 Program

ith Initialization Rungs (PLC2 Family)

START

200 PUT 000

200

020

OFF 10

062

TON

0.1

PR 005 AC 000

020

OFF 10

063 TON

0.1

PR 300 AC 000

Add These Rungs

42

252

200

035

Chapter 4

ASCII I/O Module Tutorial

035

063

000

020

063

000

020

252

251

100

247

200

252

020

END 00460

FILE TO FILE MOVE

COUNTER ADDR:

POSITION:

FILE LENGTH: FILE A:

FILE R: RATE PER SCAN:

BLOCK XFER READ

DATA ADDR:

MODULE ADDR:

BLOCK LENGTH:

FILE:

BLOCK XFER WRITE

DATA ADDR:

MODULE ADDR:

BLOCK LENGTH:

FILE:

FILE TO FILE MOVE

COUNTER ADDR:

POSITION: FILE LENGTH: FILE A: FILE R: RATE PER SCAN:

060 001

020

400 - 423 202 - 225

020

030

111

252 - 271

031

111

200 - 217

061 001

004

570 - 573

202 - 205

004

200 L

OFF 15

200 U

OFF 15

020

OFF 00

020

OFF 00

200

ON 16

200

ON 16

060 EN

060 DN

011 EN

111 DN

011 EN

111 DN

061

061 DN

200

020

Add This Rung

Add These Rungs

43

Chapter 4

ASCII I/O Module Tutorial

Setting Bits in Initialization Words

Set bits in your initialization words to select desired module features as follows:

1. Place the cursor on the file-to-file move instruction in rung 18. It

contains the file of initialization words.

2. Display the file.

Press [DISPLAY]1 for hex, or [DISPLAY] 0 for binary.

The file is displayed either in hex or binary as follows:

HEXADECIMAL DATA MONITOR

POSITION FILE DATA

001 002

0000

POSITION

001 002

BINARY

DATA MONITOR

FILE DATA

00000000 00000000 00000000 00000000

Header information was deleted for brevity.

44

3. Enter initialization data into each file word by pressing [INSERT]

after you have entered data into the command buffer at the bottom of the screen. Press [

] to move to the next file word.

Enter data in binary or hex. Binary is easier to understand because you set actual bits. Hex is faster and more convenient when you can convert from binary to hex as follows (Table 3.A)

Table 3.A Binary/Hex

Binary Hex Binary Hex Binary Hex Binary Hex

0000 0 0001 1 0010 2 0011 3

Conversion

0100 4 0101 5 0110 6 0111 7

1000 8 1001 9 1010 A 1011 B

1100 C 1101 D 1110 E 1111 F

4. Terminate data entry and return to ladder diagram.

Press [CANCEL COMMAND]

You will often use the above procedure and the procedures from chapter 1 in this tutorial.

Chapter 4

ASCII I/O Module Tutorial

Expanding the Number of Initialization Words

The module has four words that you use to select operating features. You do this by setting one or more bits for each feature that you want to use.

You increase the number of initialization words according to the module features that you want to use. For example, if you want a feature that is selected in initialization word three, you must use initialization words one, two, and three.

1. Set your module for initialization words one, two, and three using

bits 00 and 01 of initialization word one, IWl (00-01). Use the procedure in the section titled “Setting Bits in Initialization Words,” P. 3-4.

Results Position 001 contains initialization word one (IW1). This chapter will show both the binary and hex display.

File

Data

POSITION

001

Hex Binary

0020 00000000 00000010

Changing the Module's String Length (Read, Only)

String length is a 3-digit BCD number. You can set the string length in BCD, or you can set the BCD digits in binary. The binary equivalent of BCD and Hex is identical for 0 thru 9.

1. Set the string length to 15 characters in IW2 (00-13) using the

procedure in the section titled “Setting Bits in Initialization Words”.

DISPLAY The file-to-file move instruction displays your setting as follows:

File

Data

POSITION

002

Hex Binary

0015 00000000 00010101

45

Chapter 4

ASCII I/O Module Tutorial

2. Demonstrate the string length by entering 16 data characters. When

you enter the 16th data character, the module transfers the string of 15 characters to the read block transfer file in the data table, where you can observe it. (The sixteenth character is not transferred but remains as the first character in the input buffer.) Do the following example where the processor will read data from your ASCII module. Refer to the procedures in section titled “Reading Data from Your ASCII Device”, P. 1-28.

Enter ALLEN BRADLEY 12 (enter spaces as shown)

Procedure Procedure P2 Enter your data Procedure P3 Set your industrial terminal to PLC2 mode Procedure P4 Observe how data is stored in the data table

P1 Set your industrial terminal to alphanumeric mode

Results The read block transfer file displays the 15 data characters in positions 003 thru 010 (Table 3.B).

Table 3.B String

Length Display

Position

001

002 0000

003 2041 A

004 4C4C LL

005 454E EN 15

File Data

A010 or E010 status word one

status word two

ASCII Equivalent

46

006 2042 B

007 5241 RA

008 444C DL

009 4559 EY

010 2031 I

transferred

characters

The space (20) in position 003 was placed there by the module due to right justification of data.

Chapter 4

ASCII I/O Module Tutorial

Initialization Error

If the characters were not displayed when you entered them (ALLEN-BRADLEY 12), and the display of transferred data contained only the code X4XX in status word one, you have an initialization error. (X is any value.) Repeat the procedure in section titled “Setting Bits in initialization Words” (P. 3-4), exactly as shown setting IWl (00-01)=10 in binary or 2 in hex. A setting of IW1 (00-01)=11 in binary or 3 in hex will not work in this example.

Justifying Data

The module justifies data before it transfers this data to the processor data table. The module left justifies data by placing the first character in the upper byte of the first word address of the file. The module right justifies data by placing the last character in the lower byte of the last word of the file.

You can tell the difference between the storage of left and right justified data by looking at the first and last words. In left justified data, spaces or fill characters, if needed, are added to the last file word. In right justified data, space or fill characters, if needed, are added to the first file word.

If the number of characters transferred is less than the string length that you set in IW2(00-13), the module completes the string by inserting fill characters or spaces. Fill characters or spaces are stored ahead of the data (lower addresses) for right justified data, or following the data (higher addresses) for left justified data.

Demonstrating Margin Justification Storage

In this demonstration, you compare data table storage of right justified data with left justified data. When the module operates in data mode, margins are right justified (default) unless you select left justified. The demonstration in the section titled “Changing the Module’s String Length (Read, Only)” showed data table storage of right justified data (Table 3.B). In this demonstration, you set the margin justification bit IW3(03) for left justification, repeat the procedures in “Changing the Module’s String Length (Read, Only)” (P. 3-5) and compare the two displays.

1. Set IW3(03) for left justification using the procedure in section titled

“Setting Bits in Initialization Words”

47

Chapter 4

ASCII I/O Module Tutorial

Display Your file-to-file move instruction displays your setting as follows:

File

Data

POSITION

003

Hex Binary

0008 00000000 000010000

2. Repeat step 2 of section titled “Changing the String Length.”

Results The read block transfer file displays the 15 data characters in

positions 003 thru 010 with the data left justified (Table 3.C).

Table 3.C

Length, Left Justified

String

POSITION

001 002 003 004 005 006 007 008 009 010

FILE DA

E010

0000 414C 4C45

4E20

4252

4144 4C45

5920

3120

ASCII Equivalent

status word one status word two A L L E N B R A D L E Y 1

48

The module placed the space (20) in position 010 because it left justified the data.

Displaying Right Justified Data

In this demonstration, assume that your margin justification bit IW3(03) had been reset for right justification (in data mode, only), and that initialization words one and two are set as follows: IW1=0002 and IW2=0015.

1. Use file-to-file move instruction to store data you want write block

transferred to your industrial terminal for display. Load your file-to-file move instruction (rung 15) exactly as shown (Table 4.D) starting in position 001. Use the procedure in section titled “Writing Data to Your ASCII Device”, P. 1-14.

Procedure Procedure P5 Load data into the filetofile move instruction

P3 Set your industrial terminal to PLC2 mode

Table 3.D String Length, Right Justified

Chapter 4

ASCII I/O Module Tutorial

POSITION

001 002 003 004 005 006 007 008

FILE DA

2020 2020 2020 2020 2042 5241

444C

4559

ASCII Equivalent

B R A D L E Y

2. Display the data on your industrial terminal using the procedure in

entitled “Writing Data to Your ASCII Device”, P.1-14.

Set your industrial terminal to alphanumeric mode. Switch the processor mode select switch to the RUN/PROG position.

Results Your industrial terminal displays the following:

BRADLEY

BRADLEY is displayed in a position eight spaces from the left margin. This example is equivalent to transferring seven right justified data characters when the set string length is 15 characters and the data conversion is 2 ASCII characters per word.

Demonstrating EndofString Delimiter

In this demonstration you will select an end-of-string delimiter and demonstrate its use.

Select the carriage return (CR) as the end-of-string delimiter and set IW3(10-16) accordingly. The ASCII code for carriage return is 0D in hex, 0001101 in binary.

1. Set IW3(10-16) for the end-of-string delimiter, CR, and reset the

margin justification bit IW3(03) to zero for right justification using the procedure in section titled “Setting Bits in Initialization Words”, P. 3-4.

49

Chapter 4

ASCII I/O Module Tutorial

DISPLAY The file-to-file move instruction displays your setting as follows:

FILE

POSITION

003 0D00 00001

Hex Binary

101 00000000

String Length Less Than Module's String Length

Whenever the ASCII module receives an end-of-string delimiter from the ASCII device, it transfers the data in its input buffer to the processor. To demonstrate this, you will enter a data string less than the set string length as determined by IW2(00-13).

1. Enter: 12345[RETURN]

Refer to the procedures in section titled “Reading Data from Your ASCII Device”, P. 1-10.

Procedure Procedure P2 Enter your data Procedure P3 Set your industrial terminal to PLC2 mode Procedure P4 Observe how data is stored in the data table

P1 Set your industrial terminal to alphanumeric mode

Results The read block transfer file displays the five character string in positions 003 thru 010 (Table 3.E).

410

Table 3.E

Length < String Length, Right Justified

String

POSITION

001 002 003 004 005 006 007 008 009 010

FILE DA

E011

0000 2020 2020 2020 2020 2020 2031 3233 3435

ASCII Equivalent

status word one status word two

1 2 3 4 5

Chapter 4

ASCII I/O Module Tutorial

Notice the following:

The new string (data and fill characters) completely replaced the

previous data. The data is right justified. Fill character spaces (20) were added by the ASCII module.

String Length Greater Than Module's String Length

When the module receives a string of data greater than the set string length, it does the following:

Immediately transfers the number of characters equal to its set string

length to the processor. Sets bit 14 in status word one, Input String>Maximum, SW1(14). Bit

14 is immediately reset when the processor confirms receipt of data. Retains the balance of data in its input buffer. Transfers the balance of data with new data when it receives enough

new data to complete the string, or when the new data contains an

end-of-string delimiter.

In this demonstration you will enter a string of data greater than the set string length and observe its storage in the data table. (The set string length, IW2(00-13), is 15 characters.)

1. Enter 12345678901234567890

Do not enter [RETURN]

Refer to procedures in section titled “Reading Data from Your ASCII Device”, P. 1-10.

Procedure Procedure P2 Enter your data Procedure P3 Set your industrial terminal to PLC2 mode Procedure P4 Observe how data is stored in the data table

P1 Set your industrial terminal to alphanumeric mode

Results The read block transfer file displays the number of characters equal to the string length, 15, in positions 003 thru 010 (Table 3.F).

411

Chapter 4

ASCII I/O Module Tutorial

Table 3.F Transfer

of Full String

POSITION

001 002 003 004 005 006 007 008 009 010

FILE DA

E011

0000 2031 3233 3435 3637 3839 3031 3233 3435

ASCII Equivalent

status word one status word two 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5

Notice how the 15 characters of the string are stored (right justified), and that the module added one fill character.

Characters 6, 7, 8, 9, and 0 remain in the module’s input buffer. They will be erased in step 2 because the procedure clears the input buffer.

2. Enter: 12345678901234567890ABCDEFG[RETURN]

Refer to procedures in section title “Reading Data from Your ASCII Device” if necessary.

Procedure Procedure P2 Enter your data Procedure P3 Set your industrial terminal to PLC2 mode Procedure P4 Observe how data is stored in the data table

P1 Set your industrial terminal to alphanumeric mode

Results Two transfers took place in step 2 (Figure 3.2). The second transfer wrote over the first, and is displayed in the read block transfer file (Table 3.G).

Figure 3.2 Division

of Data Between Two T

1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 A B C D E F G

1st transfer

15 characters

ransfers

2nd transfer

terminated by [RETURN]

11834

412

Table 3.G

ransfer of Balance of String

Chapter 4

ASCII I/O Module Tutorial

POSITION

001 002 003 004 005 006 007 008 009 010

FILE DA

E011

0000 2020 2020 3637 3839 3041 4243 4445 4647

ASCII Equivalent

6 7 8 9 0 A B C D E F G

Your program must include instructions for processing new data read from the module. If not, data in your read block transfer file will be written over in the next read block transfer.

You can do this by examining whether status word two (SW2) contains data, using a greater-than instruction. When the value in SW2 is greater than zero (new data flag), move new read block transfer data to an alternate storage file. Your program can process it before it is overwritten by the next transfer of new data (Figure 3.3). Make the address of the source file of the file-to-file move instruction (file A) the same address as the read block transfer file. Also examine the BTR done bit.

Figure 3.3 Example

SW2>0

327

000

Storage

Bit FILE TO FILE MOVE

253

Programming, New Data Flag

BT Done Bit

111

035

BLOCK XFER READ

DATA ADDR:

MODULE ADDR:

BLOCK LENGTH: FILE:

COUNTER ADDR:

POSITION:

FILE LENGTH: FILE A:

FILE R: RATE PER SCAN:

030

111

252 - 271

035 001

254 - 271

Storage Bit

011 EN

111 DN

035

413

Chapter 4

ASCII I/O Module Tutorial

Removing the Fill Character

Whenever the module encounters the ASCII character that you defined in IW4(10-16) as the fill character to be removed, the module removes it from the string. Then the module transfers only data, justifies the data, and adds its own fill character. The number of fill characters that it adds is equal to the number of those it removed. (The fill character that the module inserts is described in section titled “Your ASCII Module Inserts Fill Characters”), P. 2-22. If your ASCII device uses fill characters for positioning data, you may choose not to remove them because the position has meaning.

In this demonstration you will select a fill character that the module will remove, and observe its operation.

1. Increase the number of initialization words to four by setting

appropriate bits. Set IW1=0003. Use the procedure in section titled “Setting Bits in Initialization Words”, P. 3-4

2. Select the slash symbol (/) as the fill character to be removed. The

ASCII / is 2F in hex. Set IW4=2F00.

Display The file-to-file move instruction displays your settings as follows:

FILE

POSITION

001 002 003 004

Hex Binary

0003 00000000 0000001 0015 00000000 00010101 0D00 00001 2F00 00101111 00000000

101 00000000

3. Enter: //AS//23//AS//4[RETURN]

Refer to procedures in section titled “Reading Data from Your ASCII Device” if necessary.

Procedure Procedure P2 Enter your data Procedure P3 Set your industrial terminal to PLC2 mode Procedure P4 Observe how data is stored in the data table

P1 Set your industrial terminal to alphanumeric mode

Results The module transferred the data characters, extracted the fill character, added its own fill character, and right justified the data (Table 3.H).

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Removing Header and Trailing Characters

Table 3.H Extraction

of Fill Character

POSITION

001 002 003 004 005 006 007 008 009 010

FILE DA

E011

0000 2020 2020 2020 2020 2041 5332 3341 5334

ASCII Equivalent

status word one status word two

A S 2 3 A S 4

This feature does not allow your program to add data characters in place of fill characters removed from the string. This feature changes the position of data.

When the module removes header and trailing characters from a data string, it counts only the balance of characters as data in the string. The module does not remove trailing characters until the data string exceeds the set string length. The module counts the first characters of the string as header characters, and removes them regardless of the number of characters in the string.

1. Set the number of header characters (three) and trailing characters

(four) to be removed by setting IW4(00-03) and IW4(04-07) to three and four, respectively. Use the procedure in section titled “Setting Bits in Initialization Words”, P. 3-4.

Display The file-to-file move instruction displays your setting as follows:

FILE

POSITION

004

Hex Binary

2F43 000010111 0100001

2. Enter: 1234567890123456789012

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Refer to procedures in section titled “Reading Data From your ASCII Device”, P. 1-10.

Procedure Procedure P2 Enter your data Procedure P3 Set your industrial terminal to PLC2 mode Procedure P4 Observe how data is stored in the data table

P1 Set your industrial terminal to alphanumeric mode

Results The read block transfer file displays 15 data characters (Table 3.I). Removed header and trailing characters are shown in Figure 3.4.

Table 3.I

After Removing Characters

Display

POSITION

001 002 003 004 005 006 007 008 009 010

FILE DA

E011

0000 2034 3536 3738 3930 3132 3334 3536 3738

ASCII Equivalent

status word one status word two 4 5 6 7 8 9 0 set string length= 1 2 15 data characters 3 4 5 6 7 8

416

Figure 3.4 Removed Header and T

1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2

3 header characters removed 4 trailing characters removed

railing Characters

15 character string

11835

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ASCII I/O Module Tutorial

Demonstrating Data Conversion

When in data mode, select a data conversion type compatible with the characters transmitted by the ASCII device. Your selection is limited to one of the following conversion types:

Conversion Type

2 ASCII characters per word 1 ASCII character per word

3 BCD characters per word 4 BCD characters per word

4 hex characters per word

Data Characters

ASCII standard code

0 thru 9

0 thru 9, A thru F

When operating in report generation mode, the module selects two ASCII characters per word for message characters. You choose the data conversion for message variables (BCD values) placed between delimiters. Your selection is limited to one of the following:

Conversion Type

3 BCD characters per word 4 BCD characters per word

Data Characters

0 thru 9

The manner in which the module converts data depends on the type of data conversion that you select. For example, if you load a file with ASCII characters and transfer the file to the industrial terminal for display, the module will interpret the data according to the data conversion that you selected. You will demonstrate this by transferring data in a file-to-file move instruction (Table 3.J) from processor to industrial terminal. The industrial terminal will display the data (Table 3.K) one line at a time. Each line is the result of selecting a different data conversion.

Table 3.J Storage

POSITION

001 002 003 004 005 006

File

FILE DA

3132 3334 4142 4344 20AB

CDEF

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Table 3.K

of Converted Data

Display

Line Conversion Display Notes

1 2 3 4 5

1  2 ASCII/word conversion examines the 7 bit code in each byte: AB=1010101 CD=11001 letters.) 2  Bits 1017 are not used in 1 ASCII/word conversion 3  Bits 1417 are not used in 3 BCD/word conversion

2 ASCII/word 1 ASCII/word 4 Hex/word 4 BCD/word 3 BCD/word

101=M; EF=1

1 2 3 4 A B C D + M 0 2 4 B D + 0 3132 3334 4142 4344 20AB CDEF 3132 3334 4142 4344 20AB CDEF 132 334 142 344 0AB DEF

110111

1=o (Note that lower case letters are displayed as upper case

1=+;

Verify the conversions (Table 3.K) as follows:

1. Load the file of the file-to-file move instruction (rung 15) starting at

position 001 exactly as shown in Table 3.J. Use procedure P3 and P5 from “Writing Data to Your ASCII Device”, P. 1-14.

Procedure Procedure P5 Load data into the filetofile move instruction

P3 Set your industrial terminal to PLC2 mode

2. Set initialization word one to data mode, and select three

initialization words. Set IW1=0002. Use the procedure in section titled “Setting Bits in Initialization Words”, P. 3-4.

1 2

418

3. Change your data conversion to 2 ASCII characters per word and set

the string length to 12, (IW2=0012).

4. Remove the BCD delimiter from initialization word four. Set

IW4=0000.

5. Change operation of your industrial terminal to alphanumeric mode.

Transfer data to the industrial terminal by changing the processor mode select switch to the RUN/PROG position.

Results The industrial terminal displays

1234ABCD+M0(table 4.K, line1)

6. Verify the remaining conversions in lines 2, 3, 4 and 5 (Table 3.K) by

setting IW2(16-14) as follows:

Bit

Chapter 4

ASCII I/O Module Tutorial

Setting

Selecting Report Generation Mode, Data Conversion, and BCD Delimiter

Conversion

1 ASCII/word

4 Hex/word 4 BCD/word 3 BCD/word

16 15 14

0 1 1 1 0 0 0 1 0 0 0 1

Hex Setting

IW2 = 3012 IW2 = 4012 IW2 = 2012 IW2 = 1012

Results The industrial terminal displays the corresponding line in Table 3.K.

In report generation mode you can mix BCD digits with ASCII characters. The module sets the ASCII data conversion to two ASCII characters per word. You select the type of data conversion for BCD digits (either three BCD of four BCD digits per word) in initialization word two (IW2). If you want to transfer BCD digits, increase the number of initialization words to four in IW1 and select the BCD delimiter in IW4.

In this demonstration you will select the following:

Four initialization words using IW1(00-01) Report generation mode using IW1(02-04) Data conversion of 3 BCD digits per word using IW2(14-16) Slash symbol (/) as BCD delimiter using IW4(10-16)

1. Set the bits in all four initialization words using the procedure in

section titled “Setting Bits in Initialization Words”, P. 3-4.

Display The file-to-file move instruction displays your settings as follows:

FILE

POSITION

001 002 003 004

Hex Binary

0007 00000000 000001 1015 00010000 00010101 0D00 00001 2F00 0010111

101 00000000

1 00000000

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Next, you will demonstrate the transfer of BCD digits to the data table, and observe how BCD digits are stored with ASCII characters when the data string contains both.

2. Enter: ABCD/1234567/A12

Use procedures in section title “Reading Data From Your ASCII Device” (chapter 1), if necessary.

Procedure Procedure P2 Enter your data Procedure P3 Set your industrial terminal to PLC2 mode Procedure P4 Observe how data is stored in the data table

P1 Set your industrial terminal to alphanumeric mode

Results The read block transfer file displays the 15 data characters in positions 003 thru 010 (Table 3.L).

Table 3.L

of BCD and ASCII Characters

Storage

POSITION

001 002 003 004 005 006 007 008 009 010

FILE DA

E010

0000 4142 4344

002F

0001 0234 0567

2F41

3100

ASCII Equivalent

status word one status word two A B C D / 1 2 3 4 5 6 7 / A 1

420

Notice the following:

The data string is left justified. BCD digits in the string are right justified. (The module inserted

leading zeros in positions 005 through 008.)

The number of characters transferred is 15.

3. For comparison, enter a string with a different number of BCD

values. Observe how they are stored.

Enter ABC/123456/A123

Chapter 4

ASCII I/O Module Tutorial

Results The read block transfer file displays the 15 data characters in positions 003 thru 010 (Table 3.M).

Table 3.M

of BCD and ASCII Characters

Storage

Formatting a SingleLine Message

POSITION

001 002 003 004 005 006 007 008 009 010

FILE DA

E010 0000 4142 432F 0123 0456 2F41 3132 3300 0000

ASCII Equivalent

status word one status word two A B C / 1 2 3 4 5 6 / A 1 2 3

Notice the following:

The module used fewer leading zeros. The module used one less storage word to store the 15 character string.

When your program transfers BCD values, be sure you know how the data will be stored (how leading or trailing zeros will position data into different storage addresses).

When formatting a message, you store the message text and you write program logic to insert variables into your message. Consider the message PRODUCED (quantity) PARTS. The message text is

PRODUCED....PARTS. The variable that you want to communicate is

the quantity. The variable can be timer or counter accumulated values, analog I/O values, or any other data table word, byte, or bit that changes value.

Format the message PRODUCED (quantity) PARTS as follows:

1. Create a file for your message using file A (source file) of a

file-to-file move instruction (FFM 060) in rung 17. Load your message text (Table 3.N) into file A of FFM 060 starting with position 001. Equivalent data table addresses are listed in the left-hand column, the message is tabulated in the right-hand column. Use the slash as your BCD delimiter.

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Do this using procedure P5 in section titled “Writing Data To Your ASCII Device” (chapter 2).

Table 3.N Message

File

Equivalent

ord Address

400 401 402 403 404 405 406 407 408 409

HEXADECIMAL DATA MONIT

POSITION FILE A DA

001 5052 002 4F44 003 5543 004 4544 005 202F 006 0000 007 2F20 008 5041 009 5254 010 5300

ASCII Equivalent

P R O D U C

E D

P A R T

Store the delimiter preceding the BCD value in the lower byte of the word preceding the BCD storage word. Store the delimiter following the BCD value in the upper byte of the word following the BCD storage word (Table 3.N). If necessary, add an extra space before the first delimiter to properly position it.

422

2. Program the insertion of the variable using get/put instructions. In

this example, use the accumulated value of free-running timer 065 as the variable. Your program will put this value into word 405 (position 006) of your message file (Table 3.N).

Chapter 4

ASCII I/O Module Tutorial

Do this by entering the following rungs (Figure 3.5) just ahead of the rung in which you just stored your message.

Figure 3.5 Example

065

000

Programming for the Message V

ariable

3. In this demonstration you will select the following features:

Four initialization words using IW1(00-01) Report generation mode using IW1(02-04) Data conversion of 3 BCD digits per word using IW2(14-16) Slash symbol (/) as BCD delimiter using IW4(10-16)

065 TON

.01 PR 300 AC 000

405065 PUT

000

Set the bits in all four initialization words using the procedure in section titled “Setting Bits in Initialization Words”, P. 3-4.

Display The file-to-file move instruction displays your settings as follows:

FILE

POSITI

001 002 003 004

Hex Binary

0007 00000000 000001 1015 00010000 00010101 0D00 00001 2F00 00101111 00000000

101 00000000

4. Display your message on the industrial terminal. Typically, you

would enable your message with a pushbutton switch and program logic. In this example, set your industrial terminal to alphanumeric mode and switch the processor’s mode select switch to the RUN/PROG position.

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Results Your industrial terminal displays

PRODUCED XXX PARTS

where XXX is the accumulated value of the free running timer that your program inserted.

Formatting a MultiLine Message

When formatting a multi-line or multi-column message using the industrial terminal, use the ASCII equivalent of the following control codes for positioning the message.

Control

Codes Hex or ASCII Equivalent

CTRL P

Column number

Line number

31, 32, 33,...

When you enter the ASCII equivalent of these control codes into the message file, they will position the cursor at the column and line number that you specify.

For example, suppose you want to display a column of 8-digit diagnostic codes that indicate the status of system operation. The diagnostic codes are the variable that your program moves into your message file at the appropriate addresses. In this example, set initialization words (Table

4.O) as follows:

424

Table 3.O Example

Initialization W

Initialization

Words

IW1 = 0007

IW2 = 2032

IW3 = 0D00

IW4 = 3A00 BCD delimiter is a colon (:)

ords

Report generation mode, 4 initialization words, 300 baud

4 BCD characters/word, 32 characters/string

Endofstring delimiter is carriage return

Selected Features

Chapter 4

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For a display of the following diagnostic codes

12345678 ABCD4321 FACEBAC2

your message file (Table 4.P) would appear as:

Table 3.P Example

POSITION

Message File

001 002 003 004 005 006 007 008 009 010

011 012 013 014 015 016 017 018 019

FILE DA

1041

1031 3B31 413A 1234 5678 3A00 1031 3B32 413A

ABCD

4321 3A00 1031 3B33 413A

FACE BAC2 3A0D

Description (FILE DA

CTRL P A CTRL P Column number ; Line number A BCD delimiter Diagnostic code Diagnostic code BCD delimiter CTROL P Column number ; Line number A BCD delimiter Diagnostic code Diagnostic code BCD delimiter CTRL P Column number ; Line number A BCD delimiter Diagnostic code Diagnostic code BCD delimiter EOS delimiter

TA)

Notice the following:

Home position of the cursor appears once (position 001) before you

specify line and column numbers. Column numbers remain constant at 31 in this example. Line numbers advance by one (31, 32, 33,...) in this example. BCD delimiter precedes and follows the variable. End-of-string (EOS) delimiter is placed at the end of this single string.

You would have entered zeros for your variables (diagnostic codes) in positions 005 and 006, 011 and 012, 017 and 018 when setting up your file. Your program inserts values when you enable the display.

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Verify that this message file displays the diagnostic codes as shown.

1. Load the message file into the file-to-file move instruction 9rung 15)

exactly as shown in table 3.P. Use procedures P3 and P5 from “Writing Data to Your ASCII Device”, P. 1-14.

Procedure P3 Procedure P5

Set your industrial terminal to PLC2 mode Load data into the filetofile move instruction

2. Set your initialization words (Table 4.O)

3. Change the block length of the BTW instruction (rung 17) from 16 to

22.

4. Change your industrial terminal to alphanumeric mode. Transfer

data to the industrial terminal by changing the processor mode select switch to the RUN/PROG position.

Results The industrial terminal displays the column of diagnostic codes in the upper left corner of the screen.

12345678 ABCD4321 FACEBAC2

With a read/write program, you can enter the text of your message into processor memory by using the industrial terminal as an ASCII data terminal (as compared with entering data with the data monitor mode of the industrial terminal described in the previous two examples). When entering data from an ASCII data terminal, you can use the rubout or delete key. Pressing either key deletes the previous character from the ASCII module’s input buffer. You can delete one or more characters up to the entire string bounded by the previous end-of-string delimiter.

426

NOTE: The correct operation of your module depends on proper handshake programming for read and write block transfer instructions. Be sure to read the description of handshaking in chapter 4, and study the handshake programming examples.

Rockwell Automation 1771-DA, D17716.5.13 User Manual

Specifications and Main Features

Frequently Asked Questions

User Manual

Table of Contents

Overview of This Manual

Intended Audience

Notational Conventions

Some Tips on Using This Manual

Typical Applications

What You Need to Get Started

What You Need To Get Started

Summary

Chapter Objectives

Justifying Margins, IW3(03)

Determining Block Transfer Length

Recording Bit Settings in Initialization Words

Chapter Objectives

Adding Initialization Rungs

Setting Bits in Initialization Words

Justifying Data

Removing the Fill Character

Demonstrating Data Conversion