View / the Complete Manual
D2–DCM
Data Communications
Module
Manual Number D2–DCM–M
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1
Manual Revisions
If you contact us in reference to this manual, please remember to include the revision number.
Title: DL205 Data Communications Module
Manual Number: D2–DCM–M
Issue
Date
Description of Changes
Original
5/96
Original Issue
Rev. A
5/98
Downsize to spiral
Rev. A
Minor changes
2nd Edition
2/03
Upgrade with DL06 and DirectSOFT32;
added MDM–TEL information
1
Table of Contents
Introduction
Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
The Purpose of this Manual . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Supplemental Manuals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Who Should Read this Manual . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Technical Support . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Conventions Used . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Key Topics for Each Chapter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
D2–DCM Hardware . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Applications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
As a DirectNET Interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
As an Extra Communication Port . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
As a MODBUS) Network Interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Environmental Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Operating Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Using your D2–DCM– Five Steps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2
2
2
2
2
3
3
4
5
5
6
6
7
7
7
8
Building the Cable
Building the Communication Cable . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Consideration 1: Physical Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Consideration 2: Electrical Specification RS232C or RS422 . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Consideration 3: Cable Schematics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Consideration 4: Cable Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Consideration 5: Installation Guidelines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
A Quick Test Cable . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
9
10
11
11
12
12
15
Setting the Switches
Setting the D2–DCM switches . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Host Computer or Operator Interface Connection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
DirectNET Interface Connection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
D2–DCM Switch Settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Address Selection Switch . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Online / Offline Switch . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
16
16
16
17
19
20
Insall the D2–DCM
Install the D2–DCM and Starting the Network . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Install the D2–DCM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Connect the Cables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
If you’re using DirectNET... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
If you’re using an Operator Interface or Host Computer... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
If you’re using MODBUS)... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
21
21
21
21
22
22
Verification & Troubleshooting
Verification and Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Troubleshooting Quick Steps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Troubleshooting Chart . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
23
24
25
ii
Table of Contents
Appendix A: Cable Diagrams
Point-to-Point RS232C D2–DCM as Master . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
A–2
Point-to-Point RS232C PC as Master . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A–3
Point-to-Point RS422 D2–DCM as Master . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
A–4
Point-to-Point RS422 PC as Master . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A–6
Multidrop RS422 D2–DCM as Master . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A–7
Multidrop RS422 PC as Master . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
A–9
DV–1000 Cable . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A–10
Appendix B: RLL Communications Programs
Why do you need networking instructions in your RLL? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B–2
The Master Initiates Requests . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
B–2
Why Ladder Logic? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B–2
Identifying the master and slave locations & addresses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B–4
Specifying the amount of data to transfer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B–5
Designating the master station memory area . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B–6
Identifying the slave station memory area to read or write . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B–7
Controlling the communications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B–9
Communications Special Relays . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B–9
Multiple Read and Write Interlocks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B–10
Appendix C: Using the D2–DCM with MODBUS
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
How Does the D2–DCM work with MODBUS? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
MODBUS Function Codes Supported . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
MODBUS Data Types Supported . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Determining the MODBUS Address . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
If the Host Software Requires the Data Type and Address... . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Example 1: V2100 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Example 2: Y20 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Example 3: T10 Current Value . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Example 4: C54 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
If the Host Software Requires an Address ONLY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Example 1: V2100 584/984 Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Example 2: Y20 584/984 Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Example 3: T10 Current Value 484 Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Example 4: C54 584/984 Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
C–2
C–2
C–3
C–3
C–4
C–4
C–6
C–6
C–6
C–6
C–7
C–9
C–9
C–9
C–9
Appendix D: Using the D2–DCM with Modems
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
System Components . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Possible Configurations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Choosing a Modem . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Set the D2–DCM Switches . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Baud Rate & Parity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Delay Time . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Delay Time Considerations for Networks with DL240 Slaves . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Choose the Proper Cables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Connecting a Modem to your Personal Computer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Connecting a Modem to the D2–DCM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Connecting a Modem to the DL240 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
D–2
D–2
D–3
D–3
D–4
D–4
D–4
D–5
D–6
D–6
D–7
D–7
Table of Contents
Using the MDM–TEL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
RS232 Connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
The MDM–TEL Setup Wizard . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
D2–DCM as Master . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
If You are Using a D2–DCM as Master . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Using DirectSOFT32 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Creating a Modem Link . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Modem Setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Configuring the Link . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
iii
D–8
D–8
D–8
D–9
D–9
D–10
D–10
D–10
D–14
D2–DCM
Data Communication
Module
In This Manual. . . .
— Introduction
— Building the Communication Cable
— Setting the D2–DCM Switches
— Installing the D2–DCM and Starting the Network
— Verification and Troubleshooting
Data Communications Module, 2nd Edition, 2/03
2
Introduction
Overview
The Purpose of
this Manual
This manual is designed to allow you to setup
and install your DL205 Data Communications
Module (D2–DCM). This is the only manual
you will need if you are using the D2–DCM as
an extra general purpose communication port
for your DL205 PLC system. If you plan on
using the D2–DCM as a network master or
slave for a DirectNET network, this manual
covers the basic steps for setting up the
D2–DCM and the RX/WX instructions needed
in your RLL program.
If you plan on using a personal computer as the network master, it may be helpful to
read the DirectNET manual first. In either case, the DirectNET manual can be
useful because it provides detailed descriptions of network configurations, various
cable connections, etc.
Supplemental
Manuals
Depending on which products you have purchased, there may be other manuals that
are necessary or helpful for your application. These are some suggested manuals:
User Manuals
D
DirectNET Network Guide
part number
DA–DNET–M
D
DirectSoft32 Programming Software part number
PC–DSOFT32–M
If you plan to use your D2–DCM to communicate with another PLC, you will need the
appropriate user manual for the other PLC.
If you plan to use your D2–DCM module as an interface to HMI or PC Control
software or to an Operator Interface panel, you will need to refer to the
documentation for that product.
Who Should Read
this Manual
If you need an additional communications port for your DL205 PLC and you
understand the basics of installing and programming PLCs, this is the right manual
for you. This manual gives you the information you need to set up an active port on
the D2–DCM module.
Technical Support
We strive to make our manuals the best in the industry and rely on your feedback in
reaching our goal. If you cannot find the solution to your particular application, or, if
for any reason you need additional technical assistance, please call us at
770–844–4200.
Our technical support team is glad to work with you in answering your questions.
They are available weekdays from 9:00 a.m. to 6:00 p.m. Eastern Time. We also
encourage you to visit our website where you can find technical and nontechnical
information about our products and our company.
www.automationdirect.com
Data Communications Module, 2nd Edition, 2/03
33
Introduction
Conventions Used
The “light bulb” icon in the left-hand margin indicates a tip or shortcut.
The “note pad” icon in the left–hand margin indicates a special note.
The “exclamation mark” icon in the left-hand margin indicates a warning or caution.
These are very important because the information may help you prevent serious
personal injury or equipment damage.
Key Topics for
Each Chapter
The beginning of each chapter will list the
key topics that can be found in that
chapter.
1
Data Communications Module, 2nd Edition, 2/03
4
Introduction
D2–DCM Hardware
The following diagram shows the major D2–DCM components. The address
selection switches and the communication dipswitches are of special importance.
Status Indicators
(shown below)
Online/Offline Switch
Base Connector
RS232C/RS422
Communication Port
Address Selection
Switches
DIP Switches for
communications
and protocol parameters
Self Test Indicator: ON
Module Power: ON
Send/Receive Enquiry:
FLASHING*
NK: ON if a NAK is
either sent or received
Send/Receive Header:
FLASHING*
Send/Receive Data
Packet: FLASHING*
TO: ON if a timeout has
occurred in the D2–DCM
Master Mode:
ON if master
OFF if slave
Status Indicators
* During communications only
The DL205 Data Communications Module (D2–DCM) is a general purpose
communications interface that can be used in a DL205 system that has a
D2–240/250–1/260 Central Processing Unit (CPU). The D2–DCM cannot be used
with a DL230 CPU. The module can go in any base slot, except for Slot 0, which is
next to the CPU. This module is primarily used for three reasons.
D
As a network master or slave interface to a DirectNET network
D
As an extra general purpose communications port to connect a personal
computer or operator interface
D
As a network interface to a MODBUSR network using the RTU protocol
Data Communications Module, 2nd Edition, 2/03
55
Introduction
Applications
As a DirectNET
Interface
The D2–DCM can be used as a network interface for applications that require data to
be shared between PLCs, or between PLCs and an intelligent device (such as a host
computer). The D2–DCM can be configured as either a master or slave station and
allows you to upload or download virtually any type of system data including
Timer/Counter data, I/O information, and V-memory information.
DirectNET Slaves
Slaves respond to the master’s request
DirectNET Masters
Issue requests to slave stations
Response
PC or D2–DCM
master can
communicate with
DirectNET Slaves
Request
Using a D2–DCM as a Network Master
Possible Slaves
The DL205 D2–DCM can be used with a
D2–240/250–1/260 CPU to serve as a
D
D2–240/250–1/260 CPU (bottom
network master. Your CPU must have
port)
firmware V1.8 or later. It cannot be used
D
D2–240/250–1/260 w/ D2–DCM
with a DL230 CPU. (A master is the
D
D3–330 or D3–330P w/ DCU
network station that initiates requests for
D
D3–340 (either port)
data from other stations on the network).
D
D4–430 (bottom port)
You simply use special RLL instructions (RX
and WX) inside of your RLL program to
D
D4–440 (bottom port)
initiate the data exchange. The D2–DCM
D
D4–450 (phone jack or bottom port)
takes communication requests issued by
D
Any DL405 CPU w/ D4–DCM
the PLC program instructions and
automatically converts these requests into
network commands that read data from or
write data to another network station.
The PLC program is really very simple and only requires a few instructions. Appendix
A provides an overview of the instructions. Or, see the DirectNET Manual for network
details.
Using a D2–DCM as a Network Slave
Possible Masters
The D2–DCM can also be used with a
D2–240/250–1/260 CPU to serve as a
D
D2–240/250–1/260
network slave station. It cannot be used
w/ D2–DCM
with a DL230 CPU. In this case, the
D
D3–340 CPU (bottom port)
D2–DCM “listens” to the network for any
D
Any DL405 CPU w/ D4–DCM
messages that contain the D2–DCM’s
address. The D2–DCM deciphers the
D
D4–450 CPU (bottom port)
network commands, carries out the
D
Host computer w/DirectSOFT
request to read or write data, and sends
DSData Server
confirmation and/or information to the
master station.
Data Communications Module, 2nd Edition, 2/03
6
Introduction
As an Extra
Communication
Port
As an extra communication port, the D2–DCM supports the DirectNET protocol just
like the bottom port on the D2–240/250–1/260 CPU, but at higher baud rates. In
general, if you can connect a device to the bottom port on the D2–240/250–1/260
CPU, then you can also connect the same device to the D2–DCM. These devices
can be a variety of things, such as operator interfaces or personal computers.
Since the D2–DCM does not require any programming, you can simply set the D2–DCM
communication parameters, connect the appropriate RS232C or RS422 cables, and start
transferring data.
Quickly add extra
communication ports*
* Number of D2-DCMs is limĆ
ited by the available power
budget
As a MODBUS
Network Interface
The D2–DCM can be used as a slave interface to connect your DL205 system to a
MODBUS network using the MODBUS RTU protocol. The host system must be
capable of issuing the MODBUS commands to read or write the appropriate data.
Appendix C provides additional information on using the D2–DCM as a
MODBUS slave interface. This manual does not describe the MODBUS protocol.
We recommend that you reference the Gould MODBUS Protocol Reference Guide
(P1-MBUS-300 Rev. B) for details on the protocol. There may be more recent editions
of this manual, so check with your MODBUS supplier before ordering the
documentation.
MODBUS Master
MODBUS Network using RTU Protocol
Network
Slave
As a slave station....
responding to network reĆ
quests
DL205 Slave
with D2–DCM
Data Communications Module, 2nd Edition, 2/03
Network
Slave
77
Introduction
Specifications
Environmental
Specifications
Operating Temperature
32° F to 131° F (0° to 55° C)
Storage Temperature
–4° F to 158° F (–20° to 80° C)
Operating Humidity
5 to 95% (non-condensing)
Air Composition
No corrosive gases permitted
Vibration
JIS C0040
Shock
JIS C0041
Voltage Isolation
1500 VAC, 1 minute duration
Insulation Resistance
10M ohms at 500 VDC
Noise
NEMA ICS3–304
Power Budget Requirement
300ma @ 5 VDC
Maximum number of modules
limited only by power budget
CPU Required
D2–240/250–1/260 minimum
firmware V1.8 or later
Location of module
CPU base only
any slot except Slot 0 or CPU slot
Interface
Serial RS232C / RS422
half-duplex, DTE, Asynchronous,
8 bits/character, odd or no parity
Baud Rates
300 to 38.4K baud, switch selectable
Maximum Distance
RS232C – 49ft (15 meters)
RS422 – 3300 feet (1000 meters)
Protocol
DirectNET1
K-sequence (proprietary)
MODBUS RTU
Diagnostics
Automatic check of ROM/RAM,
communications, switch settings,
and LEDs
Operating
Specifications
Note 1: Also compatible with Hostlink and/or CCM2 protocols. These names were used by previous vendors of
compatible Koyo designed products.
Data Communications Module, 2nd Edition, 2/03
8
Introduction
Using your D2–DCM– Five Steps
STEP 1. Familiarize yourself with the
communications options of
D2–DCM in the Introduction.
STEP 2. Build the communication cable
that fits your needs.
Cable
Switches
STEP 3. Set the D2–DCM switches.
(Baud rate, parity, etc).
Install
STEP 4. Install the D2–DCM in any slot
except for Slot 0, which is next to
the CPU.
Verify (Troubleshooting)
STEP 5. Verify correct network operation
by using the indicators and the
troubleshooting chart.
Data Communications Module, 2nd Edition, 2/03
99
Building the Cable
Building the Communication Cable
There are several considerations that help determine the type of cable needed for
your D2–DCM application.
1. Will the D2–DCM be physically connected in a point-to-point configuration
or multi-drop configuration?
2. What electrical specification is best for your application? RS232C or
RS422?
3. What is the cable schematic?
4. What are the relevant cable specifications?
5. What installation guidelines are necessary?
The next few pages discuss these considerations in detail.
Tip: If you need a quick test cable you may want to try our FA–CABKIT which allows
you to quickly build several different types of cables. (See page 15 for more
information). If you’re fairly comfortable with network or communications cabling
requirements, see Appendix A for detailed diagrams.
Data Communications Module, 2nd Edition, 2/03
10
Building the Cable
Consideration 1:
Physical
Configuration
The D2–DCM can be used in either a point-to-point or multi-drop configuration. A
point-to-point connection only has two stations, a master and a slave. Use the
point-to-point configuration to connect a personal computer, an operator interface,
or an intelligent device to a single D2–DCM. You must also use this configuration
when you want to connect a DirectNET master station to a single DirectNET slave
station.
Use the multi-drop configuration to connect one master to two or more slaves (90
slave maximum).
Point to Point
or
DCM
D2–DCM
DL205 Master
DirectNET PLC Slave
Multi-drop
DirectNET
Masters
DirectNET Slaves
or
D2–DCM
Data Communications Module, 2nd Edition, 2/03
11
11
Building the Cable
Consideration 2:
Electrical
Specification
RS232C or RS422
The D2–DCM can support RS232C or RS422 communication. Your application and
configuration choice will help determine which electrical specification is best for you. If
you are using multi-drop, you must use RS422. If you are using point-to-point, you may
have a choice between RS232C and RS422.
You can use RS232C if the cable length is less than 50 feet and if the cable will not be
subjected to induced electrical noise that is commonly found near welders, large motors,
or other devices that create large magnetic fields.
You must use RS422 for all other applications. RS422 allows longer cable distances (up
to 3300 feet) and provides higher noise immunity.
Consideration 3:
Cable Schematics
Although the network configuration and electrical specification are important, the type of
devices being connected to the D2–DCM are just as important. The exact cable
schematic needed really depends on a combination of all three things. There are a wide
range of possibilities when you consider that all three product families, the DL205,
DL305, and DL405 all offer DirectNET communication capabilities.
Hint: Look at Appendix A to determine a cable possibility. Some of these examples
may need to be combined to design a cable for your application.
NOTE: If you are using the D2–DCM to connect an OptiMation operator interface, you must
order our standard pre-made cable, part number OP–4CBL–2. If you are using a DV–1000,
you must build a custom cable. See the cable diagram at the end of Appendix A.
The following diagram shows the port pinouts for the D2–DCM and the bottom port of the
DL240 CPU. These are the two most likely combinations that you will use. Notice that the
D2–DCM has two sets of RS422 pins. These pins are internally connected and can make
it easier to wire multidrop connections.
D2–DCM Pinouts
RS232C
RS422*
1
RS232 TXD
RS232 RXD
RS232 RTS
RS232 CTS
+5V
0V
D2–240 Bottom Port
1
14
14
2
2
15
15
3
3
16
16
4
4
17
17
5
5
18
6
19
7
20
8
21
9
22
10
23
11
24
12
25
13
+5V
0V
RS422 RTS+
RS422 RTS–
RS422 RTS+
RS422 RTS–
RS422 CTS+
RS422 CTS–
RS422 TXD+
RS422 TXD–
RS422 RXD–
RS422 RXD+
18
6
19
7
20
8
21
9
22
10
23
11
24
12
25
13
RS422 TXD+
RS422 TXD–
RS422 RXD–
RS422 RXD+
* RS422 pins are internally connected
Pin
Port 2 Pinouts
Signal Definition
1
2
3
4
5
6
0V
5V
RS232C DTE RXD
RS232C TXD
Request to Send
0V
1
2
3
4
5
6
Phone Jack
Connector
NOTE: The DL205 CPU ports only support RS232C signal levels. If you are going to have
more than one slave station, you will have to use RS422 and a FA–UNICON RS232 to RS422
converter for each slave station. See the cable diagrams shown in Appendix A for detailed
diagrams.
Data Communications Module, 2nd Edition, 2/03
12
Building the Cable
Consideration 4:
Cable Specifications
Although many types of cables may work for your application, we recommend you
use a cable that is constructed to offer a high degree of noise immunity. A cable
constructed equivalent to Belden 9855 is sufficient. The following specifications are
to be used as a guideline.
Structure . . . . . . . . . . . . . . . . . . . . . . . Shielded, twisted-pair
(RS232C only uses two wires and a ground)
Conductor size . . . . . . . . . . . . . . . . . 24 AWG or larger
Insulation . . . . . . . . . . . . . . . . . . . . . . Polyethylene
Shield . . . . . . . . . . . . . . . . . . . . . . . . . Copper braid or aluminum foil
Impedance . . . . . . . . . . . . . . . . . . . . . 100W @ 1MHz
Capacitance . . . . . . . . . . . . . . . . . . . . 60pf / meter or less
Consideration 5:
Installation
Guidelines
Your company may have guidelines for cable installation. If so, you must check those
before you begin the installation. Here are some general things to consider.
D
Don’t run cable next to larger motors, high current switches, or
transformers. This may cause noise problems.
D
Route the cable through an approved cable housing to minimize the risk
of accidental cable damage. Check local and national codes to choose
the correct method for your application.
D
Consider redundant cabling if the application data is critical. This allows
you to quickly reconnect all stations while the primary cable is being
repaired.
Cable Shield Grounding — It is important to ground the cable shield to minimize
the possibility of noise. The preferred method is to connect one end of the cable
shield to the connector housing. If noise problems are still present and you have a
good earth ground for the cabinet, you must connect one end of the shield to the
cabinet earth ground. Don’t ground both ends of the shield because this will create
induced noise on the cable.
ÎÎÎÎÎ
ÎÎÎÎÎ
ÎÎÎÎÎ
Step 1: Strip back about 2.5” of the shield.
2.5”
Step 2: Crimp a ring connector onto the shield.
Data Communications Module, 2nd Edition, 2/03
Step 3: Secure the shield to
the connector shell.
13
13
Building the Cable
Multi-drop Termination Resistors — It is important you add termination resistors
at each end of the RS422 line. This helps reduce data errors during data
transmission. You must select resistors that match the cable impedance. For
example, a typical 22 AWG solid conductor cable with 4.5 twists per foot has a typical
impedance of about 120 ohm.
There are two ways to actually connect the resistors.
D
Line-to-Line — this method balances the receive data lines (IN+ and
IN–) and requires one resistor at each end of the line. (The cable
diagrams we’ve provided show this method, but you can use either).
D
Line-to-Ground — this method also balances the receive data lines, but
common mode noise rejection is improved significantly. This method
requires two resistors at each end of the line. Also, since there are two
resistors, the sum total of both resistors must match the cable
impedance.
The following diagram illustrates the two options.
Line-to-Line Termination for the D2–DCM
Master
Terminate
at Master
DirectNET
Slaves
120W
Resistor
Slave
Last Slave
7
10
11
12
13
GND
+RTS
–RTS
+CTS
–CTS
7
19
18
11
23
GND
+RTS
–RTS
+CTS
–CTS
14
15
16
17
+OUT
–OUT
–IN
+IN
17
16
15
14
+I
+IN
–IN
–OUT
+OUT
22
23
24
25
+OUT
–OUT
–IN
+IN
22
23
24
25
+OUT
–OUT
–IN
+IN
120W
Resistor
Line-to-Ground Termination for the D2–DCM
Master
Terminate
at Last Slave
Slave
Last Slave
7
10
11
12
13
GND
+RTS
–RTS
+CTS
–CTS
7
19
18
11
23
GND
+RTS
–RTS
+CTS
–CTS
14
15
16
17
+OUT
–OUT
–IN
+IN
9
10
16
14
+IN
–IN
–OUT
+OUT
22
23
24
25
+OUT
–OUT
–IN
+IN
62W
Resistors
62W
Resistors
Data Communications Module, 2nd Edition, 2/03
14
Building the Cable
Network Amplifiers — If you have more than 16 slave stations, you must use an
RS422 amplifier to maintain the signal levels. The best amplifiers are regenerative,
that is, they try to improve signal quality by reducing any noise signals that are
present. (They amplify the signal and not the noise if possible.) Some amplifiers are
not regenerative and amplify the noise as well as the signal. You can purchase
amplifiers from several sources. The Black Box catalog is one of many good places
to start; they sell direct. Call 1–800–555–1212 and ask the 800 directory assistance
operator for their phone number. You can also look for a amplifier supplier on the
internet. One web site to look at is www.idealsolution.com, or search for other RS422
amplifier web sites. The following diagram illustrates some instances where an
amplifier is necessary.
Serial Slave Connection
1-16 Slave Stations
RS422
Amp
Master
Station
Slave
Slave
Slave
Slave
Slave
Parallel Slave Connection
1-16 Slave Stations
RS422
Amp
RS422
Amp
Slave
Master
Station
Slave
Slave
RS422
Amp
Slave
RS422
Amp
Slave
Slave
Slave
RS422
Amp
Slave
RS422
Amp
Slave
Data Communications Module, 2nd Edition, 2/03
Slave
Slave
Slave
15
15
Building the Cable
A Quick Test Cable
AutomationDirect offers a Universal Cable Kit (part number FA–CABKIT). This
cable kit allows you to connect various types of DirectLOGIC products with an
RS232C cable. The kit consists of cable (phone cable with male plugs already
attached) and several specially wired connectors. The special connectors are a
D-sub style with built-in female phone jacks. The kit includes a wide variety of the
special connectors so you can use one kit to connect products from the different
DirectLOGIC family of products. To use the kit with the D2–DCM, just follow these
steps.
1. Plug the appropriate D-sub connector onto the D2–DCM.
2. Plug the appropriate D-sub connector onto the other device you are
connecting to the D2–DCM.
3. Connect the cable to the two D-sub connectors.
WARNING: This cable is suitable for quick testing situations and must not be used in
actual applications. This cable is not shielded and is highly susceptible to electrical
noise. Electrical noise can cause unpredictable operation that may result in a risk of
personal injury or damage to equipment. Use the cable specifications described
earlier in this manual to select a cable suitable for actual applications.
Build A Test Cable In 30 Seconds
1. Attach Universal Cable Adapter to the D2–DCM
2. Attach another Universal Cable Adapter to the
Device which will connect to the D2–DCM
3. Attach the Universal Cable
9 Pin
25 pin
Universal 9 pin
D–sub connector
Universal 25 pin
D–sub connector
Cable Kit Contains one (1) each of:
RJ12 to RJ12
nonĆshielded cable
RJ12 to RJ11
nonĆshielded cable
Phone jack to 9 pin
female D–sub connector
Phone jack to 9 pin
D–sub connector
Phone jack to 15 pin
D–sub connector
Universal 25 pin
D–sub connector
Data Communications Module, 2nd Edition, 2/03
16
Setting the Switches
Setting the D2–DCM switches
The D2–DCM has two banks of dipswitches that allow you to select the communication
parameters necessary for your application. In quite a few cases, you may not have to change
the switches at all. The D2–DCM comes set from the factory for:
D
DirectNET Slave operation
D
9600 Baud
D
Station Address 1
D
Odd Parity
D
Hex Mode
Host Computer or
Operator Interface
Connection
If you’re using a host computer or operator interface as the master station you should set the
D2–DCM to match the master station parameters. Check the documentation that came with
your computer or operator interface panel to determine the available communication
parameters.
You’ll need to know the following things.
D
Baud rate
D
Parity settings
D
Protocol required
Your operator interface must use one of the following protocols.
D
DirectNET
D
K-sequence
D
Hostlink (DirectNET was called Hostlink on the old TIt or Simaticr TI products.
Some Operator Interface manufacturers may still refer to it this way.)
D
MODBUS RTU
DirectNET Interface
Connection
If you’re using the D2–DCM as a DirectNET interface, you’ll need to know whether the
D2–DCM is being used in a master station, slave station, or peer station. Once you’ve
determined how the D2–DCM will be used, proceed with the dipswitch settings.
Master – Slave Network
Peer as Master Network
D2–DCM as Master
D2–DCM as Peer
D2–DCM as Slave
Data Communications Module, 2nd Edition, 2/03
D2–DCM as Peer
17
17
Setting the Switches
D2–DCM
Switch Settings
Once again, the switches should be set at the factory for the following type of operation.
D
DirectNET Slave
D
9600 Baud
D
Station Address 1
D
Odd Parity
D
Hex Mode
If these settings are acceptable, then you can go ahead and install the D2–DCM into the
base. If not, you’ll have to change the switch settings.
There are two small banks of switches located next to the blue rotary switches on the one of
the D2–DCM circuit boards. These dipswitches are used to select the communications
settings. The following diagram shows the switch locations and their purpose.
SW3
1
2
3
4
COM Timeout Enable
Hexadecimal Mode
Network
Protocol
Switch Positions
Protocol
1
DirectNET Slave
OFF
DirectNET Master
OFF
DirectNET Peer
ON
MODBUS RTU
ON
2
OFF
ON
OFF
ON
COM Timeout Disable
ASCII Mode
OFF ON
SW5
ON
1
2
3
4
5
6
7
8
Switch Positions
Time*
6
7
8
0 OFF OFF OFF
2 ON OFF OFF
NO Parity
5 OFF ON OFF
Set
to OFF
10 ON ON OFF
20 OFF OFF ON
50 ON OFF ON Delay Time
100 OFF ON ON
500 ON ON ON
*Delay time in milliseconds
Baud Rate
ODD Parity
Self Test
Switch Positions
Baud
1
2
3
300 ON OFF OFF
600 OFF ON OFF
1200 ON ON OFF
2400 OFF OFF ON
4800 ON OFF ON
9600 OFF ON ON
19200 ON ON ON
38400 OFF OFF OFF
OFF ON
Data Communications Module, 2nd Edition, 2/03
18
Setting the Switches
Protocol Selection: Positions 1 and 2 on SW3 select the D2–DCM protocol and the master
or slave settings. The D2–DCM primarily uses two protocols, DirectNET and MODBUS
RTU protocol. Here’s some information to help you choose.
Communications Port for DirectSOFT32 Programming: If you plan to program the CPU
through the D2–DCM, then you can use either DirectNET protocol or our proprietary
protocol, called K-sequence. Although it is not listed in the switch settings, K-sequence is
also available whenever the D2–DCM is set for DirectNET slave operation.
Computer or Operator Interface: If you’re using the D2–DCM to connect a computer or
operator interface, check your documentation to see which protocol is being used. Since the
D2–DCM is always a slave station when it’s connected to a computer or operator interface,
you should select DirectNET slave or MODBUS RTU slave. Note, there are also a handful
of operator interfaces that have been designed to use our proprietary K-sequence protocol. If
you have one of these, or if you need to use K-sequence for some reason, make sure you set
the D2–DCM for DirectNET Slave operation. Peer to Peer works in Hexadecimal mode only.
DirectNET Master / Slave: In a DirectNET master / slave network, one D2–DCM should be
set as a master and the rest should be set as slaves.
DirectNET Peer as Master: This is a variation of the master / slave protocol and should be
selected when you only have two stations that can each initiate requests. Each station must
have a D2–DCM as the network interface.
MODBUS RTU Slave: The D2–DCM can also be a MODBUS slave (in the RTU or HEX
mode). The D2–DCM cannot be a MODBUS master station. If you’re going to use
MODBUS, make sure your software package supports the DL205 products. See Appendix
C for more information.
Communication Timeout: Position 3 on SW3 selects the communication timeout. For most
cases, you should leave this switch in the OFF position. Communication Timeout Disable is
normally used only if you’re developing your own DirectNET programs. By disabling the
timeout, you can send one DirectNET component without any communication timeout
problems. If you have this timeout disabled and a communication error does occur, you must
restart communications by sending a retry or an End of Transmission (EOT) command. If you
want to know more, see the DirectNET manual for details.
ASCII / HEX Mode: Position 4 on SW3 selects between ASCII and HEX modes of data
representation. If you want the fastest communication possible, use HEX mode, which is the
default. The difference is in the way the data is represented. The same data is twice as long in
ASCII format, so if there’s more data, it takes longer to transfer. If you have a device on the network
that requires ASCII mode, then set the switch for ASCII mode, otherwise, use HEX mode.
Baud Rate: Positions 1 – 3 on SW5 are used to set the baud rate for the D2–DCM. There are
eight baud rate selections available ranging from 300bps to 38.4Kbps. All stations must
have the same baud rate before the communications will operate correctly. Usually,
you should use the highest baud rate possible unless noise problems appear. If noise
problems appear, try reducing the baud rates.
Parity: Position 4 on SW5 selects between the two parity options, odd or none. If you’re using
all DL205 equipment, you should use odd parity. Odd parity uses eleven bits total (1 start bit, 8
data bits, 1 stop bit, and 1 parity bit).
Some devices require no parity, which uses only 10 bits (1 start bit, 8 data bits, and 1 stop bit).
Self-Test: Position 5 on SW5 selects the factory self-test and should always be switched off.
If the self-test is on, the module will not operate correctly.
Response Delay Time: Positions 6–8 on SW4 set the response delay time. The delay time
specifies the amount of time the D2–DCM waits to send the data after it has raised the RTS
signal line. This is normally set to 0, and is typically only adjusted if you are using the
D2–DCM with a radio modem. If you are using the D2–DCM with a radio modem, check your
modem documentation to help you choose the proper setting. Also, if you’re considering the
use of a modem, check out Appendix D. It may be of some help.
Data Communications Module, 2nd Edition, 2/03
19
19
Setting the Switches
Address Selection
Switch
The D2–DCM station address is set by the two
rotary switches located on one of the D2–DCM’s
circuit boards. Addresses are in hexadecimal
format with valid addresses from 0 (only used
for the master station) to hexadecimal 5A. The
addresses do not have to be consecutive, but each
station must have a unique address.
The top rotary switch is used to set the most
significant digit of the HEX address. The bottom
switch is used to set the least significant digit of the
HEX address. For example, to set a D2–DCM
address of HEX 10 (decimal 16), set the top rotary
switch to 1 and the bottom rotary switch to 0. If
you’re using the D2–DCM as a master, make sure
you select address 0.
Even though the D2–DCM address is set in
hexadecimal, it’s a good idea to remember the
decimal equivalent. This is because the decimal
address is used most often. For example, a RLL
communications program, the DirectSOFT32
Programming Software, and our DSData Server all
use the decimal equivalent of the HEX address. It’s
easy to convert from hex to decimal.
Example: Switches set for 3C
X10
HEX Format
0 1 2 3 4 5 6 7 8 9
A B C
D
E
F
10 11 12 13 14 15
X1
HEX 3C
3 x 16 = 48
+
C = 12
= 60 decimal
Warning: The D2–DCM address switch settings are only read at power up. If you want to
change the address, you must remove the module from the base to access the switches.
Your system can be damaged if you install or remove system components before
disconnecting the system power. To minimize the risk of equipment damage, electrical
shock, or personal injury, always disconnect the system power before installing or removing
any system component.
Data Communications Module, 2nd Edition, 2/03
20
Setting the Switches
Online / Offline
Switch
On the front of the unit, just to the left of the LEDs,
you’ll notice a small slide switch. This switch is
labeled ON (for online) and OFF (for offline). If you
want to communicate through the D2–DCM, make
sure this switch is in the ON position.
In the OFF position, this switch logically
disconnects the D2–DCM from the network (just
as if you pulled the cable from the connector).
Once this switch is moved to the OFF position, the
D2–DCM will not communicate with the network. If
you move the switch to the ON position, the
D2–DCM will communicate with the network, but
not until the master sends another request for
communication. This does not operate like the
reset switch on many personal computers.
Data Communications Module, 2nd Edition, 2/03
21
21
Install the D2–DCM/Starting the Network
Install the D2–DCM and Starting the Network
Install the D2–DCM
The D2–DCM can go in any slot of a DL205 base except Slot 0, which is right next to
the CPU. The D2–DCM will not work in Slot 0.
If you’re using a D2–DCM as the network interface in a PLC master station,
remember to make a note of the slot location. (You will have to refer to this address at
some point.)
NOTE: The D2–DCM can not be mounted in a base that does not contain a
D2–240/250–1/260 CPU. Also, the D2–DCM requires 300mA of +5V base power.
Make sure you will not exceed the available base power budget by installing the
D2–DCM. See the DL205 User Manual for complete details on power budget
calculations.
WARNING: Your system can be damaged if you install or remove system
components before disconnecting the system power. To minimize the risk of
equipment damage, electrical shock, or personal injury, always disconnect the
system power before installing or removing any system component.
To insert the module into the base, align the circuit board(s) with the grooves on the
top and bottom of the base. Push the module straight into the base until it is firmly
seated in the backplane connector. Once the module is inserted into the base, push
in the retaining clips (located at the top and bottom of the module) to firmly secure the
module to the base.
Align module to
slots in base and slide in
Push the retaining
clips in to secure the module
to the DL205 base
Connect the Cables
Make sure you have all the cables connected and that all the network devices have
the same communication parameters (baud rate, parity, etc).
If you’re using
DirectNET...
The PLC master station must contain an RLL program that has the appropriate RX or
WX instructions necessary to initiate the communications. (See Appendix B for
details on the RX and WX instructions). The master station CPU must be in Run
mode in order to execute the communications program. The slave station CPUs do
not absolutely have to be in Run mode because the D2–DCM will still transfer the
data. Whether you put the slave stations in Run mode depends on your application
requirements.
Data Communications Module, 2nd Edition, 2/03
22
Install the D2–DCM/Starting the Network
If you’re using an
Connect the cables and follow the procedures outlined in the documentation that
Operator Interface or came with your host computer software or operator interface. You’ll have to execute
Host Computer...
your host or operator interface program before the communications can begin. For
example, if you’re using DirectSOFT32, you can just specify the station address and
start working!
If you’re using
MODBUS...
Connect the cables and follow the procedures outlined in your MODBUS Host
software package to start the communications. See Appendix C for more
information on using the D2–DCM with MODBUS protocol.
Data Communications Module, 2nd Edition, 2/03
23
23
Verification & Troubleshooting
Verification and Troubleshooting
If you have used the guidelines shown previously in Step 3, Starting the Network,
you are now ready to verify that the unit is operating properly. Check the D2–DCM
indicators to verify the D2–DCM is operating correctly. The following diagram shows
the proper indicator conditions.
Note: Online/Offline switch has been removed from the drawing for clarity.
Module Power:
ON
NK: ON if a NAK
is either sent or
received
TO: ON if a
timeout has
occurred in the
D2–DCM
MA:
ON if master
OFF if slave
OK: ON if self test is OK
EQ: Send/Receive Enquiry
FLASHING*
HD: Send/Receive Header
FLASHING*
DA: Send/Receive
Data Packet:
FLASHING*
* During Communication only
Data Communications Module, 2nd Edition, 2/03
24
Verification & Troubleshooting
Troubleshooting
Quick Steps
If the D2–DCM does not seem to be working correctly, check the following items.
These items represent the problems found most often.
1. Cable and connections. Incorrectly wired cables and loose connectors
cause the majority of problems. Verify you’ve selected the proper cable
configuration and check the cable making sure it is wired correctly.
2. Dipswitch settings. Make sure you’ve set the D2–DCM to match the
communication parameters required by the master station (D2–DCM,
operator interface or host computer).
3. Incorrect protocol. Make sure your operator interface or personal computer
software can use the DirectNET, Hostlink, CCM2, or MODBUS RTU
protocol.
4. Communications program. Check the communications program for errors.
Consult the DirectNET Manual or the manuals that came with your host
computer software or operator interface for details.
NOTE: If you need more in depth troubleshooting, see the chart on the next page. It
provides several different indicator patterns that may help identify your exact
problem.
Data Communications Module, 2nd Edition, 2/03
25
25
Verification & Troubleshooting
Troubleshooting Chart The following chart identifies the indicator status, possible cause, and corrective
off
on
flash
action for a wide variety of commonly found problems.
Master Station Indicators
Slave Station Indicators
Power or OK is off.
Possible Cause
1.Master PLC power is disconnected
2.D2–DCM is defective
Power and OK are on.
Master indicator is off.
1.Switch setting on master station is
incorrect
Power, OK, and MA are on.
1.The master station CPU not in RUN.
EQ does not come on when
the communications program is
executed.
2.Online/Offline switch is set to OFF.
Power, OK, and MA are on.
1.COM Timeout is disabled.
1.
2.
3.
3.Communications program is not
correct.
EQ stays on, but NK, TO, or
HD indicators do not come on
at all.
4.
2.RTS and CTS signals are not
looped back on the D2–DCM end
of the cable.
Power, OK, and MA are on.
1.RLL Communications program is
incorrect.
EQ stays on, and TO flashes.
5.
2.Settings are different.
Only PW and OK
OR
EQ flashes.
3.Cable problem.
Power, OK, and MA are on.
1.Settings are different.
EQ stays on, and NK flashes.
6.
2.Cable problem or Slave is offline.
EQ & NK come on
OR
EQ and HD
flash.
Power, OK, and MA are on.
1.Settings are different.
EQ and HD come on. TO
flashes.
7.
EQ & HD come on
Power, OK, and MA are on.
1.RLL Communications program is
incorrect.
EQ and HD come on. EQ goes
off. HD stays on, and NK
flashes or stays on.
8.
2.Settings are different.
EQ & HD come on
Power, OK, and MA are on.
DT is on, but NK flashes on
occasion.
THEN
EQ goes off, HD
and NK are on
1.Electrical noise.
9.
Data Communications Module, 2nd Edition, 2/03
26
Verification & Troubleshooting
Corrective Action
Switch Settings & Port Pinouts
Switch Settings
1.Check the master PLC source power.
1.
2.Replace the D2–DCM.
Switch Positions
Protocol
1
DirectNET Slave
OFF
DirectNET Master
OFF
DirectNET Peer
ON
MODBUS RTU
ON
SW3
2.
1.Disconnect the master station PLC power,
remove the D2–DCM and check positions
1 & 2 on SW3.
COM Timeout Enable
Hexadecimal Mode
1.Place the CPU in RUN mode.
3.
1.Disconnect the PLC power, remove the
D2–DCM and check position 3 on SW3.
2.Remove master station connector,
ensure that RTS & CTS are connected
according to the cable diagram.
5.
Network
Protocol
COM Timeout Disable
ASCII Mode
OFF ON
2.Set the switch to the ON position.
3.Make sure the RX or WX instruction is
being executed. Check the address,
slot number, and amount and type of
data used in the RX/WX instructions.
4.
1
2
3
4
SW5
1
2
3
4
5
6
7
8
NO Parity
Set to OFF
1.Check the address, slot number, and
amount and type of data used in the
RX/WX instructions.
Baud Rate
ODD Parity
Self Test
Switch Positions
Baud
1
2
3
300 ON OFF OFF
600 OFF ON OFF
1200 ON ON OFF
2400 OFF OFF ON
4800 ON OFF ON
9600 OFF ON ON
19200 ON ON ON
38400 OFF OFF OFF
Delay Time
OFF ON
2.Make sure baud rate, parity, and mode
(HEX/ASCII) match between the
master and slave.
3.Verify that the cable is wired properly.
6.
1.Make sure baud rate, parity, and mode
(HEX/ASCII) match between the
master and slave.
2.Verify that the cable is wired properly.
Also, make sure slave is online.
7.
1.Make sure baud rate, parity, and mode
(HEX/ASCII) match between the
master and slave.
Port Pinouts
RS232C
RS232 TXD
RS232 RXD
RS232 RTS
RS232 CTS
+5V
0V
1
14
2
15
1.Make sure the system has good earth
grounds. Only one end of the cable
shield must be grounded.
2.If you’re using RS232C, try RS422.
Data Communications Module, 2nd Edition, 2/03
15
3
3
16
16
4
4
17
17
5
5
18
6
19
7
20
22
9.
14
2
21
2.Make sure baud rate, parity, and mode
(HEX/ASCII) match between the
master and slave.
RS422*
1
9
1.Check the amount and type of data
being transferred. (Byte count may be
set to 1 or an odd number for a data
type that requires 2 bytes.)
Switch Positions
Time*
6
7
8
0 OFF OFF OFF
2 ON OFF OFF
5 OFF ON OFF
10 ON ON OFF
20 OFF OFF ON
50 ON OFF ON
100 OFF ON ON
500 ON ON ON
*Delay time in milliseconds
8
8.
2
OFF
ON
OFF
ON
10
23
11
24
12
25
13
+5V
0V
RS422 RTS+
RS422 RTS–
RS422 RTS+
RS422 RTS–
RS422 CTS+
RS422 CTS–
RS422 TXD+
RS422 TXD–
RS422 RXD–
RS422 RXD+
18
6
19
7
20
8
21
9
22
10
23
11
24
12
25
13
RS422 TXD+
RS422 TXD–
RS422 RXD–
RS422 RXD+
* RS422 pins are internally connected
Cable Diagrams
1A
A–2
Cable Diagrams
Point-to-Point
RS232C
D2–DCM as Master
These diagrams show the D2–DCM being used as the network master. The cable diagram is
the same when the D2–DCM is being used as a slave (for those connections that could have
the master/slave roles reversed). This is true for the:
Master
S
D2–DCM to D4–DCM connection
S
D2–DCM to DL305 CPU with RS232C DCU (or a D3–340 bottom port)
S
D2–DCM to DL405 CPU connection when used with a D4–450 CPU.
Possible Slaves
D2–DCM
DL405 CPU
Bottom Port
RS232C
DL405 DCM
or
DL205 DCM
2 TXD
2 TXD
3 RXD
3 RXD
4 RTS
4 RTS
5 CTS
5 CTS
7 GND
7 GND
DL405
CPU
Port #2
or
D4–DCM
Connect to any
of these devices
or
D2–DCM
or
DL305 CPU
w/ 232 DCU
DL305
w/DCU
25Ćpin Connector
Master
25Ćpin Connector
Possible Slaves
DL340 CPU
DL240 CPU
Bottom Port
Connect to any
of these devices
DL340 CPU
D2–DCM
DL450 CPU
Phone Jack
D2–DCM
RS232C
RS232C
2 TXD
1 RXD
2 TXD
1
GND
3 RXD
2 TXD
3 RXD
2
5V
4 RTS
3 RTS
4 GND
4 RTS
3
RXD
5 CTS
4
TXD
5 CTS
4P4C
7 GND
7 GND
5
RTS
6
GND
6P6C
25Ćpin Connector
Data Communications Module, 2nd Edition, 2/03
25Ćpin Connector
DL240 CPU
Bottom Port
or
DL450 CPU
Phone Jack
Cable Diagrams
Point-to-Point
RS232C
PC as Master
A–3
These diagrams show the D2–DCM being used as a slave to a personal computer. The
personal computer would have to be capable of issuing commands using either DirectNET
or MODBUS RTU protocol. A good example of this would be a personal computer running an
Excel spreadsheet connected through our DSData Server. (Sounds complicated, but it’s
really quite simple! Check out our catalog for more information on our powerful DSData
Server.)
Master
Slave
DL205 DCM
Personal Computer
D2–DCM
Personal Computer
RS232C
D2–DCM
RS232C
2 RXD
2 TXD
2 TXD
2 TXD
3 TXD
3 RXD
3 RXD
3 RXD
5 GND
7 GND
7 GND
7 GND
1 DCD
4 RTS
4 RTS
4 RTS
4 DTR
5 CTS
5 CTS
5 CTS
6 DSR
6 DSR
7 RTS
8 DCD
8 CTS
20 DTR
9Ćpin
Connector
25Ćpin Connector
25Ćpin DTE
Connector
25Ćpin Connector
Data Communications Module, 2nd Edition, 2/03
A–4
Cable Diagrams
Point-to-Point
RS422
D2–DCM as Master
These diagrams show the D2–DCM being used as the network master. The cable diagram is
the same when the D2–DCM is being used as a slave (for those connections that could have
the master/slave roles reversed). This is true for the:
S
S
Master
D2–DCM to D4–DCM connection
D2–DCM to DL405 CPU connection when used with a D4–450
Possible Slaves
DL405 CPU
Bottom Port
DL405
DCM
(or DL205
DCM)
Connect to any
of these devices
DL305
with
RS422 DCU
D2–DCM
D2–DCM
RS422
RS422
7 GND
7 GND
10 +RTS
10 +RTS
11 –RTS
11 –RTS
12 +CTS
12 +CTS
13 –CTS
13 –CTS
14 +OUT
9 +IN
15 –OUT
10 –IN
16 –IN
16 –OUT
17 +IN
14 +OUT
25Ćpin Connector
DL405
CPU
Port
25Ćpin Connector
Note: Pin numbers are correct. Pins are
shown out of order because it makes the
drawing easier to comprehend.
Data Communications Module, 2nd Edition, 2/03
7 GND
7 GND
10 +RTS
10 +RTS
11 –RTS
11 –RTS
12 +CTS
12 +CTS
13 –CTS
13 –CTS
14 +OUT
17 +IN
15 –OUT
16 –IN
16 –IN
15 –OUT
17 +IN
14 +OUT
25Ćpin Connector
D4–DCM
or
D2–DCM
or
DL305
w/DCU
25Ćpin Connector
Note: Pin numbers are correct. Pins are
shown out of order because it makes the
drawing easier to comprehend.
A–5
Cable Diagrams
Master
Possible Slaves
DL340 CPU
FA–UNICON RS232/422 Converter
DL240 CPU
Bottom Port
Connect to any
of these devices
DL450 CPU
Phone Jack
Slave Connection
D2–DCM
FA–UNICON Converter
DCE
RS422
7 GND
7 GND
10 +RTS
10 +RTS
11 –RTS
11 –RTS
12 +CTS
12 +CTS
13 –CTS
13 –CTS
14 +OUT
14 +IN
15 –OUT
15 – IN
16 –IN
16 –OUT
17 +IN
17 +OUT
25Ćpin Connector
DL340
CPU Port
TXD 2
1 RXD
RXD 3
2 TXD
GND 7
3 RTS
DTR 20
4 GND
4P4C
Note: RTS/CTS are looped back internally
Slave Connection
D2–DCM
FA–UNICON Converter
DCE
RS422
7 GND
7 GND
10 +RTS
10 +RTS
11 –RTS
11 –RTS
12 +CTS
12 +CTS
13 –CTS
13 –CTS
14 +OUT
14 +IN
15 –OUT
15 – IN
16 –IN
16 –OUT
17 +IN
17 +OUT
25Ćpin Connector
1
GND
2
5V
TXD 2
3
RXD
RXD 3
4
TXD
GND 7
5
6
RTS
GND
DTR 20
DL240 CPU
Bottom Port
or
DL450 CPU
Phone Jack
6P6C
Note: RTS/CTS are looped back internally
Data Communications Module, 2nd Edition, 2/03
A–6
Cable Diagrams
Point-to-Point
RS422
PC as Master
These diagrams show the D2–DCM being used as a slave to a personal computer. Since
most personal computers come with RS232C communication cards, we have shown an
FA–UNICON RS232/422 Converter being used to convert the signal. The personal computer
would have to be capable of issuing commands using either DirectNET or MODBUS RTU
protocol.
Slave
Master
DL205 DCM
FA–UNICON RS232/422 Converter
Personal Computer
DTE
D2–DCM
FA–UNICON Converter
DCE
2 RXD
RS232C
2 TXD
3 TXD
3 RXD
5 GND
7 GND
1 DCD
20 DTR
25 +5V
4 DTR
GND 7
7 GND
+RTS 10
10 +RTS
–RTS 11
11 –RTS
+CTS 12
12 +CTS
–CTS 13
13 –CTS
RS422
6 DSR
+IN 14
14 +OUT
7 RTS
– IN 15
15 –OUT
8 CTS
–OUT 16
16 –IN
+OUT 17
17 +IN
9Ćpin DTE
Connector
25Ćpin Connector
Note: 1. You must connect pin 20 to pin 25
2. RTS/CTS are looped back internally
and do not require external wiring.
Personal Computer
DTE
RS232C
DCE
2 TXD
2 TXD
3 RXD
3 RXD
7 GND
7 GND
4 RTS
20 DTR
25 +5V
5 CTS
D2–DCM
FA–UNICON Converter
GND 7
7 GND
+RTS 10
10 +RTS
–RTS 11
11 –RTS
+CTS 12
12 +CTS
–CTS 13
RS422
13 –CTS
6 DSR
+IN 14
14 +OUT
8 DCD
– IN 15
15 –OUT
20 DTR
–OUT 16
16 –IN
+OUT 17
17 +IN
25Ćpin DTE
Connector
Note: 1. You must connect pin 20 to pin 25
2. RTS/CTS are looped back internally
and do not require external wiring.
Data Communications Module, 2nd Edition, 2/03
25Ćpin Connector
A–7
Cable Diagrams
Multidrop
RS422
D2–DCM as Master
These diagrams show the D2–DCM being used as the network master for a network
consisting of various PLC stations using D2–DCMs, CPU ports, etc..
Master
DL205
D2–DCM Master
DL205
D4–DCM
RS422
Slaves
DL405 or
DL205 DCM
D2–DCM
RS422
DL305 w/ DCU
RS422
7
10
11
12
13
GND
+RTS
–RTS
+CTS
–CTS
7
10
11
12
13
GND
+RTS
–RTS
+CTS
–CTS
7
10
11
12
13
GND
+RTS
–RTS
+CTS
–CTS
7
10
11
12
13
GND
+RTS
–RTS
+CTS
–CTS
14
15
16
17
+OUT
–OUT
–IN
+IN
17
16
15
14
+IN
–IN
–OUT
+OUT
17
16
15
14
+IN
–IN
–OUT
+OUT
17
16
15
14
+IN
–IN
–OUT
+OUT
22
23
24
25
+OUT
–OUT
–IN
+IN
22
23
24
25
+OUT
–OUT
–IN
+IN
22
23
24
25
+OUT
–OUT
–IN
+IN
22
23
24
25
+OUT
–OUT
–IN
+IN
Termination Resistor
Termination Resistor
DL305
RS422 DCU
Master
DL205
D2–DCM Master
DL405 CPU
Port #2
RS422
Slaves
DL405 CPU
Bottom Port
DL405 CPU
Port #2
RS422
DL405 CPU
Port #2
RS422
7
10
11
12
13
GND
+RTS
–RTS
+CTS
–CTS
7
19
18
11
23
GND
+RTS
–RTS
+CTS
–CTS
7
19
18
11
23
GND
+RTS
–RTS
+CTS
–CTS
7
19
18
11
23
GND
+RTS
–RTS
+CTS
–CTS
14
15
16
17
+OUT
–OUT
–IN
+IN
9
10
16
14
+IN
–IN
–OUT
+OUT
9
10
16
14
+IN
–IN
–OUT
+OUT
9
10
16
14
+IN
–IN
–OUT
+OUT
22
23
24
25
+OUT
–OUT
–IN
+IN
DL405 Termination Resistor
CPU
Bottom Port
Termination Resistor
DL405 CPU
Bottom Port
Data Communications Module, 2nd Edition, 2/03
A–8
Cable Diagrams
DL205
D2–DCM
Master
Master
RS422 — — —
Slaves
+OUT
–OUT
–IN
+IN
14
15
16
17
+OUT
–OUT
–IN
+IN
22
23
24
25
FA–UNICON Converter
DL340
CPU
DL450
Phone Jack
7
10
11
12
13
Termination
Resistor
DL340
CPU
DL240 CPU
Bottom Port
GND
+RTS
–RTS
+CTS
–CTS
DCE
RS422
RS232
RXD 1
2 TXD
TXD 2
3 RXD
RTS 3
GND 4
20 DTR
7 GND
DL240 CPU
Bottom Port
or DL450
Phone Jack
GND
+RTS
–RTS
+CTS
–CTS
7
10
11
12
13
+IN
–IN
–OUT
+OUT
14
15
16
17
Note: RTS/CTS are looped back internally
FA–UNICON Converter
GND
1
5V
2
RXD
3
2 TXD
TXD
4
3 RXD
RTS
GND
5
6
20 DTR
DCE
RS232
7 GND
RS422
GND
+RTS
–RTS
+CTS
–CTS
7
10
11
12
13
+IN
–IN
–OUT
+OUT
14
15
16
17
RS422
Note: RTS/CTS are looped back internally
Data Communications Module, 2nd Edition, 2/03
Termination Resistor
Cable Diagrams
Multidrop
RS422
PC as Master
Master
A–9
These diagrams show how to connect a network of D2–DCMs to a personal computer.
Slaves
D2–DCM
D2–DCM
FA–UNICON RS232/422 Converter
Personal Computer
FA–UNICON Converter
DTE
DCE
2 RXD
RS232C
2 TXD
3 TXD
3 RXD
5 GND
7 GND
1 DCD
20 DTR
25 +5V
4 DTR
6 DSR
7 RTS
8 CTS
GND
+RTS
–RTS
+CTS
–CTS
7
10
11
12
13
+IN
–IN
–OUT
+OUT
14
15
16
17
D2–DCM
RS422
9Ćpin DTE
Connector
DTE
RS232C
3 RXD
3 RXD
7 GND
7 GND
4 RTS
20 DTR
25 +5V
5 CTS
6 DSR
8 DCD
20 DTR
25Ćpin DTE
Connector
7
10
11
12
13
GND
+RTS
–RTS
+CTS
–CTS
+OUT
–OUT
–IN
+IN
14
15
16
17
+OUT
–OUT
–IN
+IN
22
23
24
25
+OUT
–OUT
–IN
+IN
22
23
24
25
+OUT
–OUT
–IN
+IN
GND
+RTS
–RTS
+CTS
–CTS
7
10
11
12
13
7
10
11
12
13
GND
+RTS
–RTS
+CTS
–CTS
+IN
–IN
–OUT
+OUT
14
15
16
17
14
15
16
17
22
23
24
25
Note: 1. You must connect pin 20 to pin 25
2. RTS/CTS are looped back internally
and do not require external wiring.
25Ćpin Connector
D2–DCM
RS422
DCE
2 TXD
14
15
16
17
RS422
Termination Resistor
FA–UNICON Converter
2 TXD
GND
+RTS
–RTS
+CTS
–CTS
25Ćpin Connector
Note: 1. You must connect pin 20 to pin 25
2. RTS/CTS are looped back internally
and do not require external wiring.
Personal Computer
7
10
11
12
13
D2–DCM
D2–DCM
RS422
7
10
11
12
13
GND
+RTS
–RTS
+CTS
–CTS
+OUT
–OUT
–IN
+IN
14
15
16
17
+OUT
–OUT
–IN
+IN
+OUT
–OUT
–IN
+IN
22
23
24
25
+OUT
–OUT
–IN
+IN
25Ćpin Connector
25Ćpin Connector
Termination Resistor
Data Communications Module, 2nd Edition, 2/03
A–10
Cable Diagrams
DV–1000 Cable
Use the following cable diagram to connect a DV–1000 to D2–DCM. This is still a
simple master/slave connection, but the DV–1000 is the master and initiates the
data exchange with the D2–DCM.
DV–1000
D2–DCM
D2–DCM
DV–1000
Phone Jack style connector
(RJ12) on the back of the
DV-1000
RS232C
1
GND
TXD 2
2
5V
RXD 3
3
RXD
RTS 4
4
TXD
CTS 5
5
RTS
+5V 6
6
GND
GND 7
6P6C
25Ćpin Connector
Data Communications Module, 2nd Edition, 2/03
RLL Communications
Programs
B
Data Communications Module, 2nd Edition, 2/03
B–2
RLL Communications Programs
Why are networking instructions needed in your RLL?
The Master Initiates
Requests
Why Ladder Logic?
Since DirectNET is a master/slave network, the master station must initiate requests for
network data transfers. If you’re using a PLC as the master station, you use simple RLL
instructions to initiate the requests.
Since the D2–DCM network interface does not contain a program, you have to use the PLC to
issue the commands to tell the D2–DCM where to read or write data. The D2–DCM gets
information from the PLC and then converts the information into the appropriate DirectNET
commands. The RLL instructions use or identify the following items.
1. Uses the special relays assigned to the slot to control the communications.
2. Slot location of the D2–DCM master and the slave station address. (LD instruction)
3. Amount of data (in bytes, decimal) you want to transfer. (LD instruction)
4. Area of memory to be used by the master. (LDA instruction, see the DL205 User
Manual for a detailed memory map.)
5. Area of memory to be used by the slave, and whether it is a read or write operation.
(RX or WX instruction)
6. Interlocks for communication timing and multiple RX and WX routines.
This example reads 3 bytes of data from Slave Address #1,(starting at Y0), into the Master
PLC starting at V40600 (Control Relays).
CPU
Slot 0
Slot 1
Slot 2
Slot 3
Slot 4
Example RLL Program
Master PLC
Communication Error
SP125
Set
Y50
Communication Not Busy
SP124
LD
K201
D2–DCM Slot Slave Address
Y0 - Y17
LD
15
K3
8
Y20 - Y37
Transfer 3 bytes
LDA
O40600
Slave Address 1
Master Starting Address
Type of Operation
RX
Y0
Slave Starting Address
Slave Address 2
Data Communications Module, 2nd Edition, 2/03
0
B–3
RLL Communications Programs
B–3
This example writes 3 bytes of data from the Master Station (starting at V40600) to Y0 – Y27
in Slave Station #1.
CPU
Slot 0
Slot 1
Slot 2
Slot 3
Slot 4
Master PLC
V40600
15
8
0
DCM
V40601
Example RLL Program
16pt
Output
16pt
Output
Y0 Y20
Y17 Y37
Slave Address 1
Communication Error
SP131
Set
Y50
Communication Not Busy
SP130
LD
K401
D2–DCM Slot
Slave
Address
LD
K3
Slave Address 2
Transfer 3 bytes
LDA
O40600
Master Starting Address
Type of
Operation
WX
Y0
Slave Starting Address
The following paragraphs explain each operation and provide some helpful hints to make
your programs simple and easy to follow.
Data Communications Module, 2nd Edition, 2/03
B–4
RLL Communications Programs
Identifying the master and slave locations & addresses
The first Load (LD) instruction identifies the
slot location of the D2–DCM master and
the address of the slave station.
(Remember, the slot numbers start at 0.)
The constant (K) portion of the instruction
actually contains two pieces (bytes) of
information. The first two digits specify the
D2–DCM master location and the second
two digits specify the slave station address.
It is necessary to specify both the master
slot location and slave address because
you can have more than one D2–DCM
master in the base and you can have up to
90 slave stations for each master.
Conversion Hints!
Valid Slot Range: 0–7
Valid Slave Address: 1–90
Example
Master in Slot: 2
Slave Address: 3C HEX (60 decimal)
Convert the HEX address to decimal
0 1 2 3 4 5 6 7 8 9 A B C D E F HEX
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 DEC
HEX 3C
3 x 16 = 48
+ C = 12
= 60 decimal
NOTE: The LD instruction K value is entered in decimal, but the D2–DCM master and slave
addresses are in HEX. The HEX addresses must be converted to their decimal equivalent for
this instruction. See the conversion hints above.
This example is showing three slaves. In this case the address conversions are simple.
Check the Conversion Hints shown above for a more complex example.
Slot of D2–DCM
CPU
LD
K260
Slot 0 Slot 1 Slot 2 Slot 3 Slot 4
0
Slave Address
Slave 1
Slave 2
Slave 60
X10 = 3
X1 = C
Data Communications Module, 2nd Edition, 2/03
B–5
RLL Communications Programs
B–5
Specifying the amount of data to transfer
The second LD instruction indicates the
amount of data that needs to be transferred (in
bytes, 128 maximum). You have to specify the
amount of data in complete bytes. For
example, Y0 – Y27 would be three bytes of
data. There are 24 bits for the output range of
Y0–Y27 (these I/O addresses are in octal).
From the charts below we see that we can
obtain 8 bits per byte for this type of memory.
Therefore, 24 bits yields 3 bytes, of 8 bits each.
The charts below can be very helpful. Notice
that the different PLC families do not always
use the same types of memory or the same
byte boundaries. For example, the DL305 does
not use a separate data type for input and
output points.
LD
K201
LD
K3
Number of Bytes
in decimal
Example:
3 bytes of data to be transferred
The number of bytes specified also depends on the type of data you want to obtain. For
example, the DL405 Input points can be accessed by V-memory locations or as X input
locations. However, if you only want X0 – X27, you’ll have to use the X input data type
because the V-memory locations can only be accessed in 2-byte increments. The following
table shows the byte ranges for the various types of DirectLOGIC products.
DL 205 / 405 Memory
Bits per unit
Bytes
V memory
T / C current value
16
16
2
2
Inputs (X, GX, SP)
8
1
Outputs
(Y, C, Stage, T/C bits)
8
1
Diagnostic Status
8
1
Bits per unit
Number of
bytes
Data registers
T / C accumulator
8
16
1
2
I/O, internal relays, shift
register bits, T/C bits,
stage bits
1
1
Diagnostic Status
(5 word R/W)
16
10
DL305 Memory
Data Communications Module, 2nd Edition, 2/03
B–6
RLL Communications Programs
Designating the master station memory area
The Load Address (LDA) instruction specifies
the V memory area of the master that will be
used. This is the starting address. Additional
sequential locations may be used, depending
on the number of bytes that are being
transferred. Since all DL405 data is mapped
into V memory, you can easily access the data
you need.
If you are reading information from the slave
station, this is the destination area, or, the area
where the master will store the information.
If you are writing information to the slave
station, this is the source area, or, the area
where the master will obtain the information
that will be transferred to the slave.
LD
LD
K201
K3
LDA
O40600
Letter “O”
specifies an
Octal Address
V memory
Address
Example:
V memory location 40600 will be the starting point of the data
transfer area for the master. The following locations will be used to
store the data.
MSB
V40600
LSB
15
MSB
15
0
V40601
LSB
0
NOTE: Since V memory words are always 16 bits, you may not always use the whole word.
For example, if you only specify 3 bytes and you are reading Y outputs from the slave, you will
only get 24 bits of data. In this case, only the 8 least significant bits of the last word location will
be modified. The remaining 8 bits are not affected.
Data Communications Module, 2nd Edition, 2/03
B–7
RLL Communications Programs
B–7
Identifying the slave station memory area to read or write
The Read Network (RX) or Write Network
(WX) is the last instruction in the routine. Use
the RX if you want to read data from the slave,
or use the WX instruction if you want to write
data to the slave.
You have to specify the data type and the
starting address for the slave. (Remember,
you have to specify a data type that will work
correctly with the number of bytes specified.)
If you use the RX instruction, the data will be
read from the slave starting at the address
specified. If you use the WX instruction, the
data will be written to the slave starting at the
address specified.
LD
LD
K201
K3
LDA
O40600
Data Type
and
Address
RX
Y0
Example:
Read from slave starting at Y0.
NOTE: If you are exchanging data with a DL305 system, it is important to understand how to
reference the DL305 memory locations. For example, the DL305 I/O points are accessed with
the V data type or the GY data type, even though the DL305 does not actually have those data
types present in the CPU. The table on the next page provides a detailed cross reference.
CPU
Slot 0
Slot 1
Slot 2
Slot 3
Slot 4
Master PLC
Y0 - Y17
15
8
0
Y20 - Y37
Slave Address 1
Slave Address 2
Data Communications Module, 2nd Edition, 2/03
B–8
RLL Communications Programs
D3–330 / D3–340 CPUs
To get ...
TMR/CNT Current Values
R600
use...
V0
TMR / CNT Status Bits
use...
CT600
GY6001
R601
V1
CT601
GY6011
———
———
———
———
Data Registers
use...
R401,
R4002
V100
R403,
R4022
V101
———
———
R677
V77
CT677
GY6771
I/O Points
use...
Control Relays
use...
Shift Registers
use...
IO 000
GY01
CR160
GY1601
SR400
GY400
IO 001
GY11
CR161
GY1611
SR401
GY401
———
———
———
———
———
———
IO 157
GY1571
CR377
GY3771
SR577
GY577
TMR / CNT Status Bits
use...
Data Registers
use...
CT600
GY6001
R777,
R7762
V237
To g
get ...
D3–330P CPUs
To get ...
TMR/CNT Current Values
R600
use...
V0
R401,
R4002
R403,
R4022
V100
R601
V1
CT601
GY6011
———
———
———
———
———
———
R677
V77
CT677
GY6771
R777, R7762
V237
I/O Points
use...
Control Relays
use...
Shift Registers
use...
IO 000
GY01
CR160
GY1601
SR200
GY400
IO 001
GY11
CR161
GY1611
SR201
GY401
———
———
———
———
———
———
IO 157
GY1571
CR277
GY2771
SR277
GY477
Stage Status Bits
use...
S0
GY2001
S1
GY2011
———
———
S177
GY2771
V101
To g
get ...
To get ...
1 . You must have CPU firmware V1.9
g
yp
or greater
to use the GY data type
i th
in
the RX/WX iinstructions.
t ti
y
g
2 . Two bytes
of DL305 register
data
are returned
t
d with
ith one DL205 V
memory location.
Example:
Read current value from R400
into memory location V2000.
If you’re just obtaining I/O or
Timer/Counter values, the task is
fairly simple. But when you work
with data registers, it’s a bit more
involved. Here’s why.
To get R400, you examine the
table and find that you must use
reference V0. You will also notice
that you always get at least 2
registers! So you get R400 and
R401. Since you only want the
contents of R400, you have to
add some ladder logic to get rid of
the data from R401.
Data Communications Module, 2nd Edition, 2/03
LD
K201
LD
K2
Read 2
bytes
LDA
O2000
Store in
V2000
RX
To get R400,
use V100
V100
LD
V2000
Load
V2000
ANDD
KFF
Use ANDD
to remove
R401
OUT
Vxxxx
Store the
result in a
different V
location
B–9
B–9
RLL Communications Programs
Controlling the communications
Communications
Special Relays
Whenever communication is executed with a
D2–DCM, chances are the communication will
take longer than the actual PLC scan. If the
D2–DCM is busy, another request should not
be initiated until it is finished. Fortunately,
there is an easy solution for this.
There are two SPs for each slot in the CPU
base which are used only with the D2–DCM.
For example, slot 0 has SP120 and SP121.
SP120 is the D2–DCM Busy relay and, when
turned on, indicates the D2–DCM is busy.
SP121 indicates there is a communication
error for slot 0.
You should always use the D2–DCM Busy SP
in your RLL programs to ensure the D2–DCM
is ready.
The communication error SP is optional, but it
is a good way to monitor the communication
status in the RLL program. If you use the
communication error SP, make sure you place
it at the beginning of your communication
routines. This is because the communication
error relay is always reset (turned off)
whenever an RX or WX instruction is
executed.
Y50
SP125
Set
Communication Error
SP124
LD
K201
LD
K3
D2–DCM
Busy
LDA
O40600
RX
Y0
Special Purpose Communication Relays
I/O Slot Location
Communication Busy
Communication Error
0
N/A
N/A
1
2
3
SP122 SP124 SP126
SP123 SP125 SP127
4
5
6
7
SP130 SP132 SP134 SP136
SP131 SP133 SP135 SP137
DL205
0
1
2
3
4
5
6
7
CPU
Data Communications Module, 2nd Edition, 2/03
B–10
RLL Communications Programs
Multiple Read and
Write Interlocks
If you’re using multiple reads and writes in the
RLL program, the routines need to be
interlocked to be certain that all the routines
are executed. If the interlocks are not used,
then the CPU will only execute the first routine.
This is because the D2–DCM can only handle
one transaction at a time.
In the example, once the RX instruction is
executed, C0 is set. When the D2–DCM has
finished the communication task, the second
routine is executed and C0 is reset.
If you’re using RLL PLUS, you can just put each
routine in a separate program stage to ensure
proper execution. In most all cases, RLL PLUS
can be a more efficient way to create an
automation program.
The DirectNET manual provides a master /
slave example with both RLL and RLL PLUS
program descriptions.
Interlocking Relay
SP124 C0
LD
K201
LD
K3
LDA
O40600
RX
Y0
C0
Set
Interlocking Relay
SP124 C0
LD
K201
LD
K3
LDA
O40400
WX
Y0
C0
RST
Data Communications Module, 2nd Edition, 2/03
B–11
B–11
RLL Communications Programs
Multiple Read and
Write Interlocks
This example is showing three slaves. In this case the address conversions are very simple.
Check the Conversion Hints shown above for a more complex example.
Slot of D2–DCM
CPU
LD
K260
Slot 0 Slot 1 Slot 2 Slot 3 Slot 4
0
Slave Address
Slave 1
Slave 2
Slave 60
X10 = 3
X1 = C
Data Communications Module, 2nd Edition, 2/03
Using the D2–DCM
with MODBUS
C
Data Communications Module, 2nd Edition, 2/03
C–2
Using the D2–DCM with MODBUS
Introduction
How Does the
D2–DCM work with
MODBUS?
The D2–DCM can be used as a slave interface to a network using the MODBUS RTU protocol.
To use the D2–DCM with MODBUS, your host software must send a MODBUS function code
and a MODBUS address to specify a PLC memory location that is understood by the D2–DCM.
Host sends a
MODBUS request...
What's the status of Y0?
D2-DCM responds
Y0 is ON"
... D2–DCM
responds
with data
It would be quite difficult to discuss all of the ins and outs of MODBUS in this document.
Instead, the purpose of this Appendix is to:
D provide a quick overview of MODBUS Data Types and Function Codes.
D how to determine the proper MODBUS address necessary to allow the host
software to access various memory locations in the DL205 system.
One key point to remember is that not all host software packages using MODBUS drivers
operate exactly the same way. That is, there are a couple of different ways to achieve the
same result, especially when it comes to specifying the needed address for the PLC memory
location. Therefore, it is important that you follow the instructions for your particular software
package or network master.
Data Communications Module, 2nd Edition, 2/03
C–3
Using the D2–DCM with MODBUS
MODBUS Function
Codes Supported
C–3
The host software package reads or writes information by sending a MODBUS function code
to the D2–DCM. The following table provides a description of the MODBUS function codes
supported by the D2–DCM.
MODBUS Code
Function
DL205 Data Types
Available
01
Read a group of coils
Y, CR, T, CT
02
Read a group of inputs
X, SP
05
Set / Reset a single coil
Y, CR, T, CT
15
Set / Reset a group of coils
Y, CR, T, CT
03, 04
Read a value from one or
more registers
V
06
Write a value into a single
register
V
16
Write a value into a group
of registers
V
NOTE: The maximum MODBUS secondary address supported by the D2–DCM is 60 (5A
hex).
MODBUS Data Types You are probably accustomed to seeing data types like X input, Y output, C control relay, V
memory data registers, etc. for the various types of memory in a DL205 system. For example,
Supported
if you need to know the status of Y12, then you ask for Y12. MODBUS does not use these
same data types, so you have to determine which MODBUS data type corresponds to the
PLC memory location that you need. The following table will help.
DL205 Memory Type
Quantity1
(Decimal)
PLC Range
(Octal)
Corresponding
MODBUS
Data Type
Inputs (X)
320
X0 – X477
Input
Special Relays (SP)
144
SP0 – SP137
SP540 – SP617
Input
Outputs (Y)
320
Y0 – Y477
Coil
Control Relays (CR)
256
C0 – C377
Coil
Timer Contacts (T)
128
T0 – T177
Coil
Counter Contacts (CT)
128
CT0 – CT177
Coil
Stage Status Bits (S)
512
S0 – S777
Coil
Timer Current Values (V)
128
V0 – V177
Input Register
Counter Current Value (V)
128
V1000 – V1177
Input Register
V Memory, user data (V)
1024
V2000 – V3777
Holding Register
V Memory, user data (V)
Non–volatile
256
V4000 – V4377
Holding Register
V Memory, system (V)
106
V7620 – V7737
V7746 – V7777
Holding Register
Data Communications Module, 2nd Edition, 2/03
C–4
Using the D2–DCM with MODBUS
Determining the MODBUS Address
There are typically two ways that most host software packages allow you to specify a PLC
memory location. These are:
D By specifying the MODBUS data type and address.
D By specifying a MODBUS address only.
If the Host Software
Requires the Data
Type and Address...
Many host software packages allow you to specify the MODBUS data type and the MODBUS
address that corresponds to the PLC memory location. This is the easiest method, but not all
packages allow you to do it this way. The various MODBUS data types were presented
earlier, but they have been included again in the following table.
The actual equation used to calculate the address depends on the type of PLC data you are
using. The PLC memory types are split into two categories for this purpose.
D Discrete – X, SP, Y, CR, S, T (contacts), C (contacts)
D Word – V, Timer current value, Counter current value
In either case, you basically convert the PLC octal address to decimal and add the
appropriate MODBUS address (if required). The following tables show the exact equation
used for each group of data.
DL205 Memory Type
QTY1
(Dec.)
PLC Range
(Octal)
For Discrete Data Types .... Convert PLC Addr. to Dec.
MODBUS
Address Range
+
Start of Range
MODBUS
Data Type
+ Data Type
Inputs (X)
320
X0
–
X477
2048
–
2367
Input
Special Relays (SP)
144
SP0
SP540
–
–
SP137
SP617
3072
3280
–
–
3167
3471
Input
Outputs (Y)
320
Y0
–
Y477
2048
–
2367
Coil
Control Relays (CR)
256
C0
–
C377
3072
–
3551
Coil
Timer Contacts (T)
128
T0
–
T177
6144
–
6271
Coil
Counter Contacts (CT)
128
CT0
–
CT177
6400
–
6527
Coil
Stage Status Bits (S)
512
S0
–
S777
5120
–
5631
Coil
For Word Data Types ....
Convert PLC Addr. to Dec.
Timer Current Values (V)
128
V0
–
V177
Counter Current Values (V)
128
V1000
–
V Memory, user data (V)
1024
V2000
V Memory, user data (V)
non–volatile
256
V Memory, system (V)
106
+
Data Type
0
–
127
Input Register
V1177
512
–
639
Input Register
–
V3777
1024
–
2047
Holding Register
V4000
–
V4377
2048
–
2303
Holding Register
V7620
V7746
–
–
V7737
V7777
3984
4070
–
–
4063
4095
Holding Register
Data Communications Module, 2nd Edition, 2/03
C–5
Using the D2–DCM with MODBUS
DL250–1 Memory Type
QTY1
(Dec.)
PLC Range
(Octal)
MODBUS
Address Range
For Discrete Data Types .... Convert PLC Addr. to Dec.
+
Start of Range
MODBUS
Data Type
+ Data Type
Inputs (X)
512
X0
–
X777
2048
–
2560
Input
Special Relays (SP)
512
SP0
SP320
–
–
SP137
SP717
3072
3280
–
–
3167
3535
Input
Outputs (Y)
512
Y0
–
Y777
2048
–
2560
Coil
Control Relays (CR)
1024
C0
–
C1777
3072
–
4095
Coil
Timer Contacts (T)
256
T0
–
T377
6144
–
6399
Coil
Counter Contacts (CT)
128
CT0
–
CT177
6400
–
6527
Coil
Stage Status Bits (S)
1024
S0
–
S1777
5120
–
6143
Coil
For Word Data Types ....
Convert PLC Addr. to Dec.
Timer Current Values (V)
256
V0
–
V377
Counter Current Values (V)
128
V1000
–
V1177
V Memory, user data (V)
3072
4096
V Memory, system (V)
320
+
Data Type
0
–
255
Input Register
512
–
639
Input Register
V1400 – V7377
V10000 – V17777
768
4096
–
–
3839
8192
Holding Register
V700
V7400
448 – 768
3840 – 3735
Holding Register
–
–
V777
V7777
C–5
Data Communications Module, 2nd Edition, 2/03
C–6
Using the D2–DCM with MODBUS
Example 1: V2100
Find the MODBUS address for User V
location V2100.
1. Find V memory in the table.
2. Convert V2100 into decimal (1089).
3. Use the MODBUS data type from the table.
PLC Address (Dec.) + Data Type
V2100 = 1088 decimal
1088 + Hold. Reg. = Holding Reg. 1089
Example 2: Y20
Find the MODBUS address for output Y20.
PLC Addr. (Dec) + Start Addr. + Data Type
1. Find Y outputs in the table.
Y20 = 16 decimal
2. Convert Y20 into decimal (16).
16 + 2049 + Coil = Coil 2065
3. Add the starting address for the range
(2049).
4. Use the MODBUS data type from the table.
Example 3: T10
Current Value
Find the MODBUS address to obtain the
current value from Timer T10.
1. Find Timer Current Values in the table.
2. Convert T10 into decimal (8).
3. Use the MODBUS data type from the table.
Example 4: C54
Find the MODBUS address for Control Relay PLC Addr. (Dec) + Start Addr. +Data Type
C54.
C54 = 44 decimal
1. Find Control Relays in the table.
44 + 3073 + Coil = Coil 3117
2. Convert C54 into decimal (44).
3. Add the starting address for the range
(3072).
4. Use the MODBUS data type from the table.
Data Communications Module, 2nd Edition, 2/03
PLC Address (Dec.) + Data Type
TA10 = 8 decimal
8 + Input Reg. = Input Reg. 8
C–7
C–7
Using the D2–DCM with MODBUS
If the Host Software Some host software packages do not allow you to specify the MODBUS data type and
Requires an Address address. Instead, you specify an address only. This method requires another step to
determine the address, but it is not difficult. Basically, MODBUS also separates the data
ONLY
types by address ranges as well. This means an address alone can actually describe the type
of data and location. This is often referred to as “adding the offset”. One important thing to
remember here is that two different addressing modes may be available in your host software
package. These are:
D 484 Mode
D 584/984 Mode
We recommend that you use the 584/984 addressing mode if the host software allows
you to choose. This is because the 584/984 mode allows access to a higher number of
memory locations within each data type. If your software only supports 484 mode, then there
may be some PLC memory locations that will be unavailable. The actual equation used to
calculate the address depends on the type of PLC data you are using. The PLC memory
types are split into two categories for this purpose.
D Discrete – X, GX, SP, Y, CR, S, T (contacts), C (contacts)
D Word – V, Timer current value, Counter current value
In either case, you basically convert the PLC octal address to decimal and add the
appropriate MODBUS starting address (as required). The following tables show the exact
range used for each group of data.
Discrete Data Types
Memory Type
PLC Range
(Octal)
Address
(484 Mode)
Address
(584/984 Mode)
Data Type
GX0–GX1746
1001 – 1999
10001–10999
Input
GX1747 – GX3777
–––
11000–12048
Input
X0 – X1777
–––
12049 – 13072
Input
Special Relays (SP)
SP0– SP777
–––
13073 – 13584
Input
Global Outputs (GY)
GY0– GY3777
1 – 2048
1 – 2048
Output
Outputs (Y)
Y0 – Y1777
2049 – 3072
2049 – 3072
Output
Control Relays (CR)
C0 – C3777
3073 – 5120
3073 – 5120
Output
T0 – T377
6145 – 6400
6145 – 6400
Output
CT0 – CT377
6401 – 6656
6401 – 6656
Output
S0 – S1777
5121 – 6144
5121 – 6144
Output
Global Inputs (GX)
Inputs (X)
Timer Contacts (T)
Counter Contacts (CT)
Stage Status Bits (S)
Data Communications Module, 2nd Edition, 2/03
C–8
Using the D2–DCM with MODBUS
Word Data Types
Registers
PLC Range
(Octal)
Input/Holding
(484 Mode)*
Input/Holding
(584/984 Mode)*
V Memory (Timers)
V0 – V377
3001/4001
30001/40001
V Memory (Counters)
V1000 – V1177
3513/4513
30513/40513
V Memory (Data Words)
V1200 – V1377
3641/4641
30641/40641
V1400 – V1746
3769/4769
30769/40769
V1747 – V1777
–––
31000/41000
V2000 – V7377
–––
41025
V10000 – V17777
–––
44097
* MODBUS: Function 04 (New Feature)
The DL–250, DL–350 and DL450 will support function 04 read input register (Address
30001). To use function 04, put the number ’4’ into the most significant position (4xxx). Four
digits must be entered for the instruction to work properly with this mode.
LD
LD
K101
K4128
The Maximum constant possible is 4128. This
is due to the 128 maximum number of Bytes
that the RX/WX instruction can allow. The
value of 4 in the most significant position of the
word will cause the RX to use function 04
(30001 range).
LDA
O4000
RX
Y0
1. Refer to your PLC user manual for the correct memory mapping size of your PLC. Some of
the addresses shown above might not pertain to your particular CPU.
2. For an automated MODBUS/Koyo address conversion utility, download the file
modbus_conversion.xls from the www.automationdirect.com website.
Data Communications Module, 2nd Edition, 2/03
C–9
Using the D2–DCM with MODBUS
C–9
Example 1: V2100
584/984 Mode
Find the MODBUS address for User V
location V2100.
1. Find V memory in the table.
2. Convert V2100 into decimal (1088).
3. Add the MODBUS starting address for the
mode (40001).
PLC Address (Dec.) + Mode Address
Example 2: Y20
584/984 Mode
Find the MODBUS address for output Y20.
PLC Addr. (Dec) + Start Address + Mode
1. Find Y outputs in the table.
Y20 = 16 decimal
2. Convert Y20 into decimal (16).
16 + 2048 + 1 = 2065
3. Add the starting address for the range
(2048).
4. Add the MODBUS address for the mode
(1).
Example 3: T10
Current Value
484 Mode
Find the MODBUS address to obtain the
current value from Timer T10.
1. Find Timer Current Values in the table.
2. Convert T10 into decimal (8).
3. Add the MODBUS starting address for the
mode (3001).
Example 4: C54
584/984 Mode
Find the MODBUS address for Control Relay PLC Addr. (Dec) + Start Address + Mode
C54.
C54 = 44 decimal
1. Find Control Relays in the table.
44 + 3072 + 1 = 3117
2. Convert C54 into decimal (44).
3. Add the starting address for the range
(3072).
4. Add the MODBUS address for the mode
(1).
V2100 = 1088 decimal
1088 + 40001 = 41089
PLC Address (Dec.) + Mode Address
TA10 = 8 decimal
8 + 3001 = 3009
Data Communications Module, 2nd Edition, 2/03
Using the D2–DCM
with Modems
D
Data Communications Module, 2nd Edition, 2/03
D–2
Using the D2–DCM with Modems
Introduction
There are some applications that require a remote connection to the PLC. These remote
connections require you to use a modem to communicate between the Personal Computer and
the PLC system. Although this manual tends to focus on using the D2–DCM in networking
applications, there are a tremendous number of people who simply use the D2–DCM as an extra
communications port. The D2–DCM provides additional flexibility in configuration and baud rates
compared to the built-in port on the CPU, so it’s a logical choice for use with a modem.
It is not hard to establish remote communications with a PLC system via a modem. This
appendix provides some guidelines to help you setup the communications link.
System Components There are typically two types of communication paths for modem applications.
D Telephone modems
D Radio modems
Both serve the same basic function, which is to enable data communications over a long
distance. However, your choice really depends on your particular application. Radio modems
are typically more expensive and can be more difficult to use in some situations. But if you
don’t have phone lines or dedicated cabling in the area, your choice may be restricted to radio
modems anyway.
For the DL205 family of products, any system that is designed to handle modem
communications usually contains components from the following list.
D DL240 PLC System with D2–DCM
D PLC System with DL250–1/260 CPU bottom port
D Personal Computer
D 2 modems (one on each end)
Telephone
Modems
Radio
Modems
Data Communications Module, 2nd Edition, 2/03
D–3
Using the D2–DCM with Modems
Possible
Configurations
Even though most all systems have one or more of the system components, there are a
couple of ways that they can be used.
PC Master — Some people need to use modems between a personal computer and the PLC
system so that they can perform remote programming and/or data monitoring tasks with
PC-based software, such as DirectSOFT32 or a SCADA system. In this case, the personal
computer is the master and the PLC system is the remote slave station.
D2–DCM Master — In other situations, you may be using a D2–DCM as the remote
communications master instead of a personal computer. If you are considering this, you
must have one of the following situations.
D You have a Leased-line — You can have a leased (dedicated) phone line if
modems are used. A dedicated line is necessary because the D2–DCM cannot
issue the dial-up commands, so the carrier must be active at all times.
D You have a Radio Link — You also have the option of using radio modems.
This is useful when it is not feasible to have hard-wired communications cabling
between the remote stations.
D You have a MDM–TEL — It has the capability of on contact initiated dialing.
In either case, the cabling and setup requirements share many similarities, which are
covered later in this Appendix.
PC as Master
D2–DCM as
Master
Choosing a Modem
D–3
D2–DCM as
Slave
D2–DCM as
Slave
With today’s prices, it is possible to buy a high quality modem for a reasonable price. It is
recommended that you purchase a modem not because it is inexpensive, but because it has
a good reputation. This will save you money (and time) over the long run. It is also suggested
that you spend a few extra dollars to get an external modem if possible. The internal versions
typically do not have status indicator lights and are much harder to debug during setup, or
modem communication failure.
We recommend using AutomationDirect’s MDM–TEL, Industrial Telephone Modem. It is
an external modem which is DIN–rail mounted. This is a rugged industrial telephone modem
which has been designed for operation in electrical enclosures which are installed in harsh
environments. This MDM–TEL supports all standard Hayes AT commands, Fax Class 1 and
Class 2 commands and S–registers, therefore it can be setup as an external modem on any
PC. This industrial modem is compatible with any telecommunications or dial–up networking
software. The MDM–TEL is also fully supported by AutomationDirect’s technical support
team. More detailed information can be located at www.automationdirect.com.
Data Communications Module, 2nd Edition, 2/03
D–4
Using the D2–DCM with Modems
Set the D2–DCM Switches
For the most part, we suggest that you follow the setup instructions shown earlier in this
manual. That is, choose the protocol you’re using, set the station address, etc. However,
there are a couple of important differences which are discussed here.
Baud Rate & Parity
It is important that you select the following communications parameters when you use the
D2–DCM for remote communications.
D 9600 baud
D NO parity
The parity setting is most important. Most popular modems cannot transmit an odd number
of bits per character. If parity is enabled, each character would consist of 1 start bit, 8 data
bits, 1 parity bit and 1 stop bit, making a total of 11 bits per character. Since this is an odd
number, the modem would not work properly. You can experiment with the baud rate settings,
but make sure all components are set to the same baud rate.
Delay Time
If you’re using a radio modem, you may have to set a delay time for the communications. This
time is necessary to allow time for the radio to “key-up” before the data is transmitted. You
must match the settings required by your modem.
SW5
1
2
3
4
5
6
7
8
NO Parity
Set to OFF
Switch Positions
Time*
6
7
8
0 OFF OFF OFF
2 ON OFF OFF
5 OFF ON OFF
10 ON ON OFF
20 OFF OFF ON
50 ON OFF ON
100 OFF ON ON
500 ON ON ON
Delay Time
(see modem
manual)
*Delay time in milliseconds
ON
Data Communications Module, 2nd Edition, 2/03
OFF ON
Baud Rate
(9600 shown)
Switch Positions
Baud
1
2
3
300 ON OFF OFF
600 OFF ON OFF
1200 ON ON OFF
2400 OFF OFF ON
4800 ON OFF ON
9600 OFF ON ON
19200 ON ON ON
38400 OFF OFF OFF
D–5
D–5
Using the D2–DCM with Modems
Delay Time
Considerations for
Networks with DL240
Slaves
A couple of scenarios have been mentioned where you may be using a D2–DCM connected
to a modem as the master station and a DL240 CPU connected to a modem as the slave
station. If you have such a situation, there are a couple of things that you may have to take into
consideration.
If you are using a radio modem connected to
the bottom port of a DL240, you will probably
have to set a delay time for the CPU port. You
can do this by loading a BCD value into
V7632. This is a special V-memory location
which defines the baud rate and/or time delay
for the bottom port. It is recommended that
you do this on the first scan within your ladder
program. The following diagram provides a
table of the settings and an example of some
simple setup logic that could be included in
your RLL program.
V7632
MSB
X
LSB
X
X
X
Delay Codes
Baud Rate Codes
00 No delay
00: 300 baud
01 2ms delay
01: 1200 baud
02 5ms delay
02: 9600 baud
03 10ms delay
03: 19200 baud
04 20ms delay
05 50ms delay
06 100ms delay
07 500ms delay
Example:
First Scan Only, Load Delay Time of 5ms & Baud Rate of 19200 for Bottom Port
V7632
Delay Time
Baud Rate
Bit 15 14 13 12 11 10 9 8
0 0 0 0 0 0 1 0
0
7 6 5 4
3
2 1 0
0 0 0 0 0 1 1 0
0
2
3
Delay Codes
Baud Rate Codes
00 No delay
00: 300 baud
01 2ms delay
01: 1200 baud
02 5ms delay
02: 9600 baud
03 10ms delay
03: 19200 baud
04 20ms delay
05 50ms delay
06 100ms delay
07 500ms delay
Setup Rung
SP0
Use the LD (Load) instruction to load the BCD codes for
each parameter into the accumlator. The number 0203 is
just the code used for our particular example, which is a
5ms delay, 19.2K baud.
LD
K203
Place the value in memory location V7632
OUT
V7632
Main Ladder Program Begins
X
X
After the parameter setup rung(s) above, we begin the
normal ladder program. Use your actual program for this
and the following rungs.
XX
KKVV
Y
Data Communications Module, 2nd Edition, 2/03
D–6
Using the D2–DCM with Modems
Choose the Proper Cables
The exact cables needed really depend on your particular application. In any case, you will
probably use one or more of the following connections.
D Personal Computer to modem connection
D Modem to D2–DCM connection
D Modem to DL240 connection
Connecting a Modem Your choice of cable for connecting the modem to your personal computer depends on
whether you have a 9-pin port or a 25-pin port on your COM card. In either case, it’s usually
to your Personal
easier to buy a cable rather than make one. It is suggested that you check your modem
Computer
documentation to see what the manufacturer recommends. If your documentation does not
recommend a cable, you could try the following sources.
D Radio Shack
D Black Box Catalog
Some users prefer to build their own cable. Here are the pinouts that are usually required.
Again, check your modem documentation for the exact requirements.
NOTE: The 9-pin diagram can be confusing because it shows TXD – TXD and RXD – RXD
connections. This is actually correct because the 9-pin connector conforms to the IBM
standard for DTE and the 25-pin side conforms to the standard for DCE. This results in the
slight confusion over the terminology used to label the TXD and RXD pins.
25 to 25 Pin Cable
9 to 25 Pin Cable
PC
Modem
PC
Modem
RS232C
RS232C
2 RXD
2 TXD
3 TXD
3 RXD
5 GND
2 TXD
2 TXD
3 RXD
3 RXD
7 GND
7 GND
7 GND
1 DCD
8 DCD
4 RTS
4 RTS
4 DTR
20 DTR
5 CTS
6 DSR
6 DSR
6 DSR
5 CTS
6 DSR
7 RTS
4 RTS
8 DCD
8 DCD
8 CTS
5 CTS
20 DTR
20 DTR
9 RI
22 RI
9Ćpin
Connector
25Ćpin Connector
Data Communications Module, 2nd Edition, 2/03
25Ćpin Connector
25Ćpin Connector
D–7
D–7
Using the D2–DCM with Modems
Connecting a Modem The PLC is on the other end of the remote communication link and will typically have a
D2–DCM as the communications interface. Just as you needed a cable to connect your
to the D2–DCM
personal computer to the modem, you’ll also need a cable between the PLC system
(D2–DCM) and the receiving modem. Since the D2–DCM and the modem have 25-pin
connectors, use the straight-through 25-pin to 25-pin cable diagram shown here.
25–pin to 25-pin Cable
Phone Modem
D2–DCM
25–pin to 25-pin Cable
Radio Modem
RS232C
D2–DCM
RS232C
2 TXD
2 TXD
2 TXD
2 TXD
3 RXD
3 RXD
3 RXD
3 RXD
7 GND
7 GND
7 GND
7 GND
4 RTS
4 RTS
4 RTS
4 RTS
5 CTS
5 CTS
5 CTS
5 CTS
6 DSR
6 DSR
8 DCD
8 DCD
20 DTR
20 DTR
Tip: You can use our D3–DSCBL–2 with a null modem adapter to quickly build a cable which
can connect the modem to the D2–DCM (also used with the MDM–TEL modem). You’ll need
the following parts, which can be obtained at most any electronics store. Since there seems
to be a Radio Shack on every corner, we’ve included their part numbers.
D
D
D
D3–DSCBL–2 — Automationdirect DL305 Programming Cable
26–1496 — Radio Shack DB25 Null Modem Adapter
26–1388 — Radio Shack DB25 Male to DB9 Male Adapter
25 to 25 Pin
Null Modem
Adapter
9 to 25 Pin
Adapter
9 Pin Adapter
Connecting a Modem Use the cable diagram shown here to connect
a modem to the bottom port of a DL240 CPU.
to the DL240
RJ12 to 25-pin Cable
DL240
Modem
RS232C
4 TXD
2 TXD
3 RXD
3 RXD
1 GND
7 GND
2 5V
4 RTS
5 RTS
6 GND
5 CTS
6 DSR
RJ12 Connector
8 DCD
20 DTR
25Ćpin Connector
Data Communications Module, 2nd Edition, 2/03
D–8
Using the D2–DCM with Modems
Using the MDM–TEL
RS232 Connections
The MDM–TEL industrial modem, which is fully supported by AutomationDirect, is a
sensible choice for your application. The MDM–TEL User Manual, which can be downloaded
from the AutomationDirect website, will provide more detailed information.
Use a straight–through or equivalent serial cable to connect the modem’s RS232 female port
(DB9 cable male end) to the RS232 male port on a PC or other “Data Terminal Equipment”
(DTE) device (DB9 cable female end). The diagram below details the pin–out of a
straight–through serial communications cable suitable for connecting a DCE device
(MDM–TEL) to a DTE device (PC, PLC or other device). A sutable DB9 RS–232 cable is
provided with the MDM–TEL.
MODEM RS232 Connections
Cable for MODEM to IBM COM Port
IBM COM Port
(Female DB9)
1
2
3
4
5
6
7
8
9
MODEM RS232 Port
(Male DB9)
DCD
DCD
RXD
RXD
TXD
TXD
DTR
DTR
GND
GND
DSR
DSR
RTS
RTS
CTS
CTS
RI
RI
1
2
3
4
5
6
7
8
9
MODEM CABLE WIRING
(Standard DB9 Cable)
To simplify the connection between the D2–DCM and the MDM–TEL modem purchase a
D3–DSCBL–2 cable available from AutomationDirect. The null modem adapter supplied
with the modem is required when using this cable.
NOTE: A suitable serial cable and a null modem adapter are provided with the MDM–TEL.
The provided null modem adapter is not required for normal serial communications
between the MDM–TEL and a PC.
The MDM–TEL Setup A modem setup utility is provided on the MDM–TEL CD to help you quickly configure the
modem. In most applications, no knowledge of modem AT commands or S register contents
Wizard
is necessary. Pre–configured profiles, for common situations, are provided for convenience.
Data Communications Module, 2nd Edition, 2/03
D–9
Using the D2–DCM with Modems
D–9
D2–DCM as Master
If You are Using a
D2–DCM as Master
If you are using the D2–DCM as a master connected directly to a modem, then you must be
using one of two types of modems. In either case, there are no special procedures that are
required.
D Leased-line Modem — If you have a leased line modem, it tries to establish
communications with the remote modem as soon as the power is turned on.
The carrier stays active as long as the power is on. (That’s why they call them
“dedicated” lines.) After they are connected, the RX or WX instruction in the
RLL program controls the data transmission between the stations. That is,
when the RX or WX is executed, it automatically causes the D2–DCM’s
Request to Send line to go high. The modem responds with a Clear to Send
and the communications begins.
D Radio Modems — If you have a radio modem, the RX or WX instruction in the
RLL program controls the data transmission between the stations. That is,
when the RX or WX is executed, it automatically causes the D2–DCM’s
Request to Send line to go high. The modem responds with a Clear to Send
and the communications begins. The radio modem broadcasts the request and
(hopefully) the remote station will receive it and respond accordingly.
D MDM–TEL — If you have a MDM–TEL modem, you can have the modem dial a
preconfigured phone number by applying +24VDC to the “From PLC” terminal
on the modem. When the modem connects to another modem and establishes
communications, the modem will then apply +24VDC to the “to PLC” terminal.
This input to the PLC is used to initiate RX or WX commands from the RLL
program. If you do not have either a sourcing DC output or a sinking DC input,
you will need to add a D2–08CDR module to your system in order to control the
signals to/from the modem.
Data Communications Module, 2nd Edition, 2/03
D–10
Using the D2–DCM with Modems
Using DirectSOFT32
Creating a Modem
Link
Modem Setup
DirectSOFT32 uses Telephony Application Programming Interface (TAPI) for
modem configurations. The TAPI protocol allows applications to control modems or
other telephony devices for operations such as dialing, answering, or disconnecting
a connection. With the TAPI protocol, all of the modem support is centralized by the
Windows operating system.
By using the TAPI interface, you will use the Windows modem setup utilities to
configure the modem. Configuring the modem in this matter should simplify the
setup process and allow you to select the most recent drivers for your modem.
If there is an existing modem connected to your PC for Internet or fax use, the
modem setup will have to be changed. Some of the features will have to be disabled
in order to communicate to the PLCs. To avoid making any changes to the existing
modem configuration, you will need to install the same modem a second time.
Windows will change the name by adding a number to the end i.e., “modemname#2”
each time you add the same modem to your PC. Refer to your PC and/or modems
installation manual for additional information on setting up your modem.
The first series of examples were performed in Windows 2000 and will illustrate how
to configure the modem connected to your PC. The examples may differ depending
on your Windows operating system.
1. Install the modem if not already installed. Refer to the modem’s
documentation for installation information. If the modem is to be used for
other devices you will need to install it a second time.
2. Once you have successfully installed the modem, you will need to edit its
properties. In the Windows Start field, select Settings > Control Panel.
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Using the D2–DCM with Modems
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3. Select the Phone and Modem Options icon. A dialog box with all available
modems installed will appear.
4. Choose the Modems tab, then click on Properties at the bottom.
5. Choose 9600 as the Maximum Port Speed.
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Using the D2–DCM with Modems
6. Select the Advanced tab and click on Change Default Preferences.
7. Make Port speed 9600, and choose None for Flow control.
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Using the D2–DCM with Modems
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8. Click on the Advanced tab and choose 8 Data bits, None Parity and 1 Stop
bits.
9. Click OK until all dialog boxes are closed. This will setup your Windows
driver so DirectSOFT32 can use the Windows TAPI control when
accessing the modem.
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Using the D2–DCM with Modems
Configuring the
Link
With the modem configured correctly, the link to the PLC can now be established.
The next series of steps will provide the information necessary for configuring the
link using DirectSOFT32.
1. The LinkWizard can automatically determine the majority of the
communication settings; however, you will need to manually setup the
modem specific information (modem type, phone number, etc.). To
activate the Link Wizard in the Launch Window, right click on the Comm
Links icon in the DSLaunch tree and select Add Link.
Right Click to
select Add Link
2. Select Modem as the device and click the Next button.
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Using the D2–DCM with Modems
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3. The Configure Link dialog box should now be present. First, choose the
PLC family and the PLC CPU Type. Click once on the appropriate item in
the PLC Family and a list of available CPUs for that family will appear to the
right. Click once to select the appropriate PLC Type. Also give the link a
name and description.
4. Click the Port tab of the dialog to display the port configuration dialog. This
dialog allows you to setup up the port to match your modem’s configuration.
Follow the steps below:
D Select Modem in the Devices column.
D Select the modem type that you configured earlier in this procedure.
You can verify or modify the settings by clicking on the Properties
button or you can create a new modem by clicking on the Add button.
D Enter the dialing information for your modem.
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Using the D2–DCM with Modems
5. Click the Protocol tab to display the communication protocol dialog box.
This dialog allows you to further define the communication parameters.
D
Select the communication protocol to use. Refer to the chart in
Appendix A for a breakdown of the various CPUs, and which protocols
are supported on which ports.
D If the PLC has been given a node Address other than 1, enter the new
address now.
D You can adjust the time–outs and retries on this dialog, however, the
default values should work for you.
6. Click the Accept button to save this link configuration. The following dialog
will appear. If you click Yes, DirectSOFT32 will dial the modem and attempt
to verify that it can communicate with the PLC connected to the other
modem using the parameters defined in the link. DirectSOFT32 will
hang–up once the connection is made. If you click No, the link configuration
will simply be saved to disk.
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Using the D2–DCM with Modems
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7. After successfully creating a link, the Launch Window will have an entry for
the link that you have created. The name that you assigned to the link
should appear in the menu tree under the Comm Links icon. If the link is
highlighted, the main launch window screen will change with all of the links
information displayed.
Data Communications Module, 2nd Edition, 2/03
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