Allen Bradley Micrologix 1000 Setup Guide

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Introduction

The Allen Bradley Micrologix 1000 PLC has a single serial port which can be used to communicate with Fernhill SCADA. The serial port on the PLC is an 8 pin mini-DIN socket located on the left side of the PLC.

Connection Cables

The Micrologix 1000 PLC can connect directly to a serial port on a Personal Computer (PC). The serial port on a PC is usually a 9 pin D-subminiature connector. These cables are suitable to connect the PLC to a computer with a 9 pin D-subminiature connector:

As an alternative you can create your own cable using this wiring:

Micrologix 1000

8 pin mini-DIN plug wiring side shown
PC
D-Subminiature connector DE-09 socket wiring side shown
GND25GND
RTS38CTS
RXD43TXD
DCD51DCD
CTS67RTS
TXD72RXD
4 + 6DTR + DSR

Note: All other pins not shown in the above diagram have no connection.

Configuring Serial Communications

Setting up a serial communication link can be difficult because of the wide variety of communication options. For example:

For Fernhill SCADA to communicate with a Micrologix 1000 PLC, both need to use the same communication options. There are a two main ways to achieve this:

Manual Configuration

The default communication settings for the Micrologix 1000 are:

ParameterValue
Baud Rate9600
ProtocolDF1 Full Duplex
Error CheckCRC
Node Address1

The Fernhill SCADA configuration that corresponds to these defaults is:

Allen Bradley Serial Port
ModeBaud=9600 Parity=N Data=8 Stop=1
ProtocolDF1 Full Duplex
ErrorCheckCRC
Allen Bradley PLC
Destination Node1

Configuring the Micrologix 1000 Serial Port using RSLogix 500

You can use RSLogix 500 to configure the Micrologix 1000 Serial Port.

1. Open a project in RSLogix 500 and in the Project window select Channel Configuration:

Channel Configuration selected in RSLogix 500

2. Double click the Channel Configuration branch to open the DF1/485 Configuration window:

Micrologix 1000 channel configuration window

Note: Choose DF1 as the primary protocol. Fernhill SCADA does not currently support DH485.

Recovering From Non-Default Communication Settings

If you change the communications settings away from the default it is quite easy to lose communication from both Fernhill SCADA and RSLinx. You can recover from this situation using the 1747-UIC (Universal Serial Bus (USB) to DH-485 Interface Converter):

  1. Plug the 1747-UIC into the Computer running RSLinx
  2. Install the 1747-UIC following the instructions in the manual 1747-IN063.
  3. Connect the 1747-UIC to the MicroLogix 1000 using a 1761-CBL-PM02 cable (or similar).

    Note: When the MicroLogix 1000 detects a communication failure on the serial port, it will switch between DF1 and DH485 protocols. The MicroLogix 1000 continues to switch until communication is re-established. The 1747-UIC should re-establish communications with the MicroLogix 1000 using DH485.

  4. Change the configuration of the MicroLogix 1000 serial port using RSLogix 500.

Further Information

Allen Bradley serial channel

For information about Allen Bradley serial channel configuration.

Allen Bradley PLC

For information about Allen Bradley PLC Tag configuration.

Serial Communications

For background information on serial communications.

Allen Bradley Driver

For information about the Allen Bradley Driver.

Glossary

For the meaning of terms used in Fernhill SCADA.