Applies To:
  • CitectSCADA 5.xx

Can Citect communicate to the Allen-Bradley MicroLogix 1000 & 1500 series PLCs? 

The MicroLogix supports the DF1 protocol. However, some models only support full duplex communications as follows:
MicroLogix 1000 Series C and earlier Full-duplex DF1 only
MicroLogix 1000 Series D Both Full & Half duplex DF1
MicroLogix 1500 Both Full & Half duplex DF1

Citect drivers supporting Full Duplex DF1 include:

a) the ABRSLINX driver. This requires Rockwell's RSLinx OEM product. An application note is available on the FTP site.

Citect drivers supporting Half Duplex DF1 includes:

a) The KE500 driver, included standard with the product.

b) When configuring the Micrologix device for Half Duplex, Slave, it must be changed from CRC to BCC Error checking. This change will make RSLinx unable to talk to the MicroLogix device. However, it has to be done for Citect to communicate with it. If you wish to switch it back you should contact Allen Bradley for default CRC settings.

c) When communicating Half Duplex the com forms are identical to setting up a SLC 500, however, if not using a DF Module you will only need to supply the node address in the IO Device form e.g. just the number 1 as opposed to 1,1.

d) When using RSLinx to change the settings on the Micrologix, make sure that you check the baud rate as RSLinx always sets it back to 1200bps.