Allen Bradley MicroLogix 1200 Connection Guide
Help Contents
- Fernhill SCADA
- Help
- Drivers
- Allen Bradley
- MicroLogix 1200 Connection Guide
Introduction
This article is a guide to connect an Allen Bradley MicroLogix 1200 PLC
to Fernhill SCADA.
The Allen Bradley MicroLogix 1200 PLC has one or two serial ports
which can be used to communicate with Fernhill SCADA.
- Communication channel 0 is an 8 pin mini-DIN socket located on the top left of the unit.
- The optional Prog/HMI port is an 8 pin mini-DIN socket located on the left side of the unit.
Note: Only selected models support the Prog/HMI port.
To connect a MicroLogix 1200 PLC to Fernhill SCADA these steps are required:
- Obtain a connection cable and connect the MicroLogix 1200 PLC to a Windows Computer running RSLogix 500.
- Configure the MicroLogix 1200 PLC using RSLogix 500.
- Configure Fernhill SCADA.
Connection Cables
The MicroLogix 1200 PLC can connect directly to a serial port on a 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:
- 1761-CBL-AP00: 0.5 m length
- 1761-CBL-PM02: 2 m length
- 1761-CBL-PM05: 5 m length
- 1761-CBL-PM10: 10 m length
As an alternative you can create your own cable using this wiring:
MicroLogix 1200
|
PC
|
| GND | 2 | 5 | GND |
| RTS | 3 | 8 | CTS |
| RXD | 4 | 3 | TXD |
| DCD | 5 | 1 | |
| CTS | 6 | 7 | RTS |
| TXD | 7 | 2 | RXD |
| | | 4 + 6 | DTR + DSR |
Note: All other pins not shown in the above diagram have no connection.
Configuring the MicroLogix 1200 Serial Port using RSLogix 500
You can use RSLogix 500 to configure the MicroLogix 1200 Serial Port.
-
Open a project in RSLogix 500 and in the Project window select Channel Configuration:
-
Double-click the Channel Configuration branch to open the Channel Configuration window:
Note: The Fernhill SCADA Allen Bradley Driver supports DF1 Full Duplex and DF1 Half Duplex Slave.
-
Select the Channel 0 tab:
Field configuration notes:
-
For the Driver field choose either DF1 Full Duplex or DF1 Half Duplex Slave.
-
If you are using DF1 Half Duplex, enter the Node Address.
-
Choose whether to use Even Parity or No Parity.
Even Parity offers improved communication error detection in exchange for slightly greater overhead.
-
Choose a baud rate.
-
Choose the Error Detection method.
-
Leave the remaining fields at their default values.
-
Click OK to save the configuration.
If you have changed Channel 0 configuration away from the defaults, you may receive a warning about loss of communication.
Ignore the warning and, after communication is lost, change the configuration of the AB_DF1 device in RSLinx to match.
-
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 Communications Toggle Push Button located near the Channel 0.
For more information refer to the MicroLogix 1200 Programmable Controllers User Manual 1762-UM001.
Configure Fernhill SCADA
There are two methods to configure Fernhill SCADA to communicate with a MicroLogix 1200 PLC:
-
The easiest way is to use an autodetect wizard.
The wizard will try different settings to work out the correct Fernhill SCADA configuration.
Use one of these wizards depending whether the PLC was configured to use Full Duplex or Half Duplex Slave:
- Manually configure Fernhill SCADA to match the configuration of Channel 0 of the MicroLogix 1200 PLC.
Manual Configuration
The default communication settings for Channel 0 on the MicroLogix 1200 are:
| Parameter | Value |
|---|
| Baud Rate | 19200 |
| Protocol | DF1 Full Duplex |
| Error Check | CRC |
| Node Address | 1 |
The communication settings for Prog/HMI port are:
| Parameter | Value |
|---|
| Baud Rate | 19200 |
| Protocol | DF1 Full Duplex |
| Error Check | CRC |
| Node Address | 1 |
The Fernhill SCADA configuration that corresponds to the defaults for Channel 0 and the Prog/HMI port is:
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.