A.3.8 Explicit Messaging with the LM10 Relay

CHAPTER A:

LM10 AND ALLEN-BRADLEY SLC500 VIA DEVICENET™

ZIn RSLogix 500, open the O0-Outputand I1-Inputforce files.

FIGURE A–8: Input Force File

ZTo turn on the Run1 contactor, toggle the O:1/16 bit to 1. To turn off Run1, set this bit to 0.

The status of the Run1 contactor is indicated by the I:1.1/18 bit.

The remote (DeviceNet) control is indicated by the I:1.1/21 bit.

The COS I/O messaging data is available in the I1-Input file, bits I:1.1/24 and onwards.

A.3.8 Explicit Messaging with the LM10 Relay

Explicit messages are stored in the data table of the SLC processor in hexadecimal format. An M0 copy instruction is used to send the message to the 1747-SDN-scanner module. The scanner module takes the data and formats it into the proper protocol for transmission on the DeviceNet network. The destination device (node) receives the message, takes the appropriate action depending upon the type of command, and formats a reply message for transmission on the network. The scanner module receives the message that contains information on the success or failure of the command. The SLC processor uses an M1 copy instruction to get the message response information from the scanner module. The status information is placed in the SLC processor data table.

The discussion of Explicit Messaging will be limited to only the elements necessary to allow this application to function and those that are necessary to provide basic understanding of the application logic.

Explicit Messaging uses Class, Instance, and Attribute data to build its message structure.

Upon completion of a successful transaction, the logic automatically increments the TXID# and is ready for the next transaction. Also, the Status data received will be reflected in Status Word I:s.0 Bit-15. A “1” will be shown for successful message completion. Refer to the table below for all Status codes as provided by ODVA specification.

LM10 MOTOR PROTECTION SYSTEM – INSTRUCTION MANUAL

A–21

Page 95
Image 95
GE Motor Protection System instruction manual A.3.8 Explicit Messaging with the LM10 Relay