Allen-Bradley PLC-5 via TCP/IP - Hardware Setup

There are two methods of connecting to a PLC-5 series PLC:

• direct

• offlink.

Direct Ethernet

PLC-5E model PLCs can support a direct Ethernet connection. In this case all that you need to do is assign the PLC an IP address, by using the BOOTP utility (refer to the Allen-Bradley documentation). Test that the network and IP address is valid by using the Ping program (explained in the TCP/IP Guide).

Offlink

In the case that you have PLC-5s that are not Ethernet capable, or if they are connected via DH or DH+ through a 5/250 or AB-KA, you can still access them through Offlink Addressing. Follow these general steps:

1. Set up the PLC 5/250 resource manager or AB-KA module. Assign the IP address, and test that it is valid by using the Ping program (explained in the TCP/IP Guide).

2. Set up the PLC-5 for communications on the DH or DH+ network to which it is connected. Set the Node Address, Baud rate etc.

3. Check that you can communicate to the PLC using offlink addressing. You can use the utility accompanying the Allen-Bradley Interchange software to verify that you can communicate from a PC over Ethernet.

Hints and Tips

• The EI module may be mounted in the rack of the PLC-5/250, or PLC-5 series controllers, or built into the PLC-5 *E controllers. The module has a DIX connector that requires an AUI cable to attach via a transceiver to the thin or thick Ethernet cable.

• The EI module requires a Signal Quality Error (SQE) test - also known as a heartbeat. Set your Ethernet transceiver with the SQE test enabled.

• If your machine is very slow and has a heavy processing load, you may find that this protocol is generating timeout errors (decimal 21). Setting the [Kernel]Idle parameter less than the default may fix this problem.

Plant SCADA Computer Setup

Setup your specific Ethernet card as required and confirm basic network communications before proceeding with the communications configuration for the ABTCP driver. Refer to the documentation accompanying your hardware for instructions.

Setup the TCP/IP protocol on your Plant SCADA computer.