ML_EN object

The ML_EN object represents the physical Allen-Bradley MicroLogix processor with the built-in EtherNet/IP port or coupled with the Ethernet Interface module for MicroLogix and CompactLogix (1761-NET-ENI).

• 1763-L16xxx

• 1761-L10xxx, 1761-L16xxx, 1761-L20xxx, 1761-L32xxx

• 1762-L24xxx, 1762-L40xxx

• 1764-LSP, 1764-LRP

This object is hosted by CIP Network Object

Add ML_EN objects to your ABCIP hierarchy

1. Select and right-click on the New_PORT_CIP_000 object.

2. Select Add ML_EN Connection from the shortcut menu. A New_ML_EN_000 object is created.

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

This configuration view has six parameters, five of which are configurable:

• Processor Type: (not configurable) Information provided automatically by the OI Server Manager (MicroLogix).

• Host Name: The Host Name or IP Address of the destination MicroLogix processor or 1761-NET-ENI module connected to a MicroLogix processor.

  • The Host Name is defined in the system Host file, usually found in: \Windows\system32\drivers\etc\hosts folder.

  • The number of characters cannot be more than 255. The field cannot be blank.

• Reply Timeout: Time (in seconds) the Communication Driver will wait for the acknowledgement after it sends out a message. The message will be resent when time-out occurs.

  • The valid range is 1 - 300 seconds.

  • The default value is 15.

• Connection Timeout: Time (in milliseconds) allowed for establishing a socket connection to a target device.

  • The valid range is 10 - 10000 milliseconds.

  • The default value is 2000.

  • The connection timeout is used if the ML_EN object is beneath PORT_CIP.

• Use CIP Connection: This option specifies if the CIP connection should be used to communicate with the MicroLogix controller. It must be selected to support MicroLogix model 1100/1400-series controllers with direct CIP connection. It is optional for all other MicroLogix models.

  • The default value is True.

    Note: The number of CIP connections in the controllers are limited (See Max CIP Connections below).

• Maximum 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.

The logical endpoint for each branch of the ABCIP hierarchy tree is always a Processor Type node, which represents the controller device.