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EIP PCCC CompactLogix Programming

General

The Allen-Bradley CompactLogix PLC uses MSG function blocks to create the Client interface for initiating the EIP PCCC transfers. For Write messages, the MSG function block specifies the source location of the data to be sent to the appropriate dw210 addresses. For Read messages, the MSG function block specifies the destination for the data when a range of dw210 addresses is queried.

For the following PLC programming example, the previously described drive.web Configuration with eight contiguous parameters mapping to PLC addresses N27:0-7 (Writes) and N29:0-7 (Reads) is used.

For the CompactLogix PLC, two MSG blocks must be instantiated in the program. One for writing the data to the dw210 and another for reading the data. There will be a different Message Control block for the read and the write transfers of data.

Write MSG Block

The Write MSG block's configuration information is stored in dwblock02_msg_ctrl Message File as shown below:

cl_wmsg

Message Configuration

Clicking on the small gray button to the right of the dwblock02_msg_ctrl name opens a Message Configuration window. Select the Configuration tab.

Configuration Tab

Refers to the MSG function block's interaction with the local CompactLogix processor.

cl_wmsg_cfg

Message Type: PLC5 Typed Write Type of EIP PCCC command.
Source Element: dwblock02_data[0] Local PLC starting address of the write data.
Number Of Elements: 8 Number of 16-bit parameters to write.
Destination Element: N27:0 Starting address in the dw210 of the write data.

Communications Tab

The Communications tab is used to set the destination address of the EIP PCCC Server, in this case, a dw210.

cl_wmsg_com

Path: LocalENB Name of the Ethernet module in the local PLC.
2 Port number for the Ethernet port in local PLC.
192.168.1.71 IP address of the dw210.
Communication Method: CIP Route the message through the Ethernet network. cia the Control and Information Protocol (CIP).

Tag Tab

The Tag tab associates the MSG block with the appropriate Message Control block.

cl_wmsg_tag

Name: dwblock02_msg_ctrl Storage location for all the Message Control parameters.

Read MSG Block

The Read MSG block's configuration information is stored in dwblock01_msg_ctrl Message File as shown below:

cl_rmsg

Message Configuration

Clicking on the small gray button to the right of the dwblock01_msg_ctrl name opens a Message Configuration window. Select the Configuration tab.

Configuration Tab

Refers to the MSG function block's interaction with the local CompactLogix processor.

cl_rmsg_cfg

Message Type: PLC5 Typed Read Type of EIP PCCC command.
Source Element: N29:0 Starting address in the dw210 of the read data.
Number Of Elements: 8 Number of 16-bit parameters to write.
Destination Element: dwblock01_data[0] Local PLC starting address of the read data.

Communications Tab

The Communications tab is used to set the destination address of the EIP PCCC Server, in this case, a dw210.

cl_rmsg_com

Path: LocalENB Name of the Ethernet module in the local PLC.
2 Port number for the Ethernet port in local PLC.
192.168.1.71 IP address of the dw210.
Communication Method: CIP Route the message through the Ethernet network. cia the Control and Information Protocol (CIP).

Tag Tab

The Tag tab associates the MSG block with the appropriate Message Control block.

cl_rmsg_tag

Name: dwblock01_msg_ctrl Storage location for all the Message Control parameters.

Sample Program

The preceding sections only cover the basic MSG block's configuration. A sample program with detailed triggering, error recovery, and comms link performance indicators are included in a complete sample CompactLogix program available at driveweb.com. A savvy-ready complementary loopback dw210 configuration is included in this download.

Click here to download the sample program.