Applies To:
  • CitectSCADA
  • CitectHMI

The primary intention for the ABCLX driver is for ControlLogix PLCs. These processor modules have an RS232 port on the front (which talks DF1 protocol), however SCADA communications to these PLCs is usually via the backplane that the processor sits in. Usually an Ethernet module will sit in the same backplane as the processor and it is via this that the ABCLX driver will communicate to the processor. The driver supports routing (where there may be various other networks between the ethernet module and the processor [such as ControlNet]). 

OK having established a standard application. There are various other pieces of AB equipment that the driver can talk to. This is because the driver supports the EIP/native protocol. So it should be able to talk to anything that uses the Ethernet/IP protocol and uses tag names rather than the older method of register addresses (such as N7:0 etc). This typically includes;


CompactLogix PLCs with an ethernet port on the CPU appear to the driver the same as a ControlLogix Processor in slot 0 with an ethernet module in the same backplane. I.e. the default configuration. ControlNet models may also work if routed via an ethernet module in a ControlLogix backplane.


Using a FlexLogix controller with 1788-ENBT communication daughtercard. Is the same as above. Other communications cards may also work if routed via an ethernet module in a ControlLogix backplane.

Note that the driver was only tested with ControlLogix applications and as such the default parameters are aimed at this level. Some tuning may be required on both the Citect and PLC ends because these platforms do not have the same performance as ControlLogix.

Other Logix platforms (such as ProcessLogix and DriveLogix) will also be likely to work however have not been confirmed. There is one report of the ABCLX driver working successfully with SoftLogix.

Some known exceptions;

Using RSLinx it is possible to connect to either ControlLogix CPUs or CompactLogix CPUs which only have a serial port) via an 1761-NET-ENI module which is a EIP (ethernet) to DF1 (serial) gateway. This allows you to access tags directly using the tag names (so it is using EIP native) however because it uses a special mode known as "exclusive" mode the ABCLX driver does not support this.

It is also possible (using RSLinx) via ethernet to connect to MicroLogix PLCs or other older DF1 serial devices using the 1761-NET-ENI module. However these devices use the older register based addressing (such as N7:0) which in this case means it is not EIP/native it is EIP/PCCC. The ABCLX driver does not support this. Update: this application is supported via ABMLXEIP driver (which uses EIP/PCCC method)

In these cases it is possible for comms via the serial port directly using our KE protocol. Although in the case of the ControlLogix / CompactLogix you need to map the tag names to "PLC5 files" and this can be very limiting and is not recommended. Update: ABDF1FD driver is preferred to KE.

The ABCLX driver (from V3.02.00.000 onwards) now supports exclusive (serial) connection to
CompactLogix/ControlLogix PLC via Ethernet Interface module (1761-NET-ENI). To
enable this support, a ini parameter need to be set in [ABCLX] or
[IOServerName.PortName] section. For more information see the topic "Setting up an exclusive connection" in the ABCLX driver help.


ABCLX, ABLOGIX, AB, Allen-Bradley, Allen Bradley, Rockwell, ControlLogix, Control Logix, EIP, PCCC, CompactLogix, Compact Logix, FlexLogix, Flex Logix