PLC5_CN object

The PLC5_CN object represents the physical Allen Bradley ControlNet-capable PLC-5 processor.

• 1785-LxxC

This object is hosted by PORT_CN.

Add the PLC5_CN object to your ABCIP hierarchy

1. Select and right-click on the New_PORT_CN_000 object.

2. Select Add PLC5_CN Connection from the shortcut menu. The New_PLC5_CN_000 object is created.

3. Rename the newly created object as appropriate. The PLC5_CN Parameters configuration view is displayed.

The configuration view contains five parameters, four of which are configurable:

• Processor Type: (not configurable) The information is automatically provided (PLC-5).

• ControlNet Address: The node address on the Control Net network (Octal).

  • The valid range is 1 - 99 decimal.

  • The default value is 1 (one).

• Source Link ID: The source link ID of the module. This link ID has to match what has been defined in the ControlNet Routing table for the ControlNet network.

  • The valid range is 1 - 199.

  • The default value is 1 (one).

• Reply Timeout: Enter the maximum amount of time (in seconds) that the Communication Driver will wait for a response from the controller.

  • The valid range is 1 - 300 seconds.

  • The default value is 15 seconds.

• Max CIP Connections: The maximum number of CIP connections that can be originated from the Communication Driver to the PLC. The number of CIP connections should be configured based on the load of messages that are sent to the device, and the hardware capabilities of the PLC processor. When multiple CIP connections are configured, the ABCIP Communication Driver distributes the number of messages across these connections to enable faster processing of the messages. For example:

  • If Max CIP Connections is configured as 1, then all messages will be polled through the single CIP Connection, one message at a time.

  • If Max CIP Connections is configured as 4 and there are 10 messages in the queue, then these 10 messages will be polled through 4 CIP Connections. 4 messages will be sent to PLC immediately, and the other 6 messages will be in queue. The next 4 messages will be sent to PLC after the first 4 messages are processed. The process will continue until all messages in the queue are processed.

  • The valid range is 1 - 31.

  • The default value is 4 (four).

    Note: For each CIP connection established, the PLC allocates certain resources to handle the connection. If too many CIP connections are established by the Communication Driver, the PLC processor allocates more resources for the CIP, which might affect the performance of other operations. For example, with 31 connections, the data updates become extremely sluggish since the PLC ran out of resources to handle the runtime logic and updating the control items. This is why it is important to configure the number of CIP Connections based on the hardware capabilities of the PLC processor.