GE Multilin G60 Generator Protection System B-5APPENDIX B B.2 MODBUS FUNCTION CODESBB.2.3 EXECUTE OPERATION (FUNCTION CODE 05H)This function code allows the master to perform various operations in the relay. Available operations are shown in the Sum-mary of operation codes table below.The following table shows the format of the master and slave packets in Modbus RTU. Modbus TCP/IP ADUs have aMBAP instead of slave address, and CRC is in another stack layer. The example shows a master device requesting theslave device 11h (17 decimal) to perform a reset. The high and low code value bytes always have the values “FF” and “00”respectively and are a remnant of the original Modbus definition of this function code.B.2.4 STORE SINGLE SETTING (FUNCTION CODE 06H)This function code allows the master to modify the contents of a single setting register in an relay. Setting registers arealways 16 bit (two byte) values transmitted high order byte first. The following table shows the format of the master andslave packets in Modbus RTU. Modbus TCP/IP ADUs have a MBAP instead of slave address, and CRC is in another stacklayer. The example shows a master device storing the value 200 at memory map address 4051h to slave device 11h (17dec).Table B–5: MASTER AND SLAVE DEVICE PACKET TRANSMISSION EXAMPLEMASTER TRANSMISSION SLAVE RESPONSEPACKET FORMAT EXAMPLE (HEX) PACKET FORMAT EXAMPLE (HEX)SLAVE ADDRESS 11 SLAVE ADDRESS 11FUNCTION CODE 05 FUNCTION CODE 05OPERATION CODE - high 00 OPERATION CODE - high 00OPERATION CODE - low 01 OPERATION CODE - low 01CODE VALUE - high FF CODE VALUE - high FFCODE VALUE - low 00 CODE VALUE - low 00CRC - low DF CRC - low DFCRC - high 6A CRC - high 6ATable B–6: SUMMARY OF OPERATION CODES FOR FUNCTION 05HOPERATIONCODE (HEX)DEFINITION DESCRIPTION0000 NO OPERATION Does not do anything.0001 RESET Performs the same function as the faceplate RESET key.0005 CLEAR EVENT RECORDS Performs the same function as the faceplate CLEAR EVENT RECORDS menucommand.0006 CLEAR OSCILLOGRAPHY Clears all oscillography records.1000 to 103F VIRTUAL IN 1 to 64 ON/OFF Sets the states of Virtual Inputs 1 to 64 either “ON” or “OFF”.Table B–7: MASTER AND SLAVE DEVICE PACKET TRANSMISSION EXAMPLEMASTER TRANSMISSION SLAVE RESPONSEPACKET FORMAT EXAMPLE (HEX) PACKET FORMAT EXAMPLE (HEX)SLAVE ADDRESS 11 SLAVE ADDRESS 11FUNCTION CODE 06 FUNCTION CODE 06DATA STARTING ADDRESS - high 40 DATA STARTING ADDRESS - high 40DATA STARTING ADDRESS - low 51 DATA STARTING ADDRESS - low 51DATA - high 00 DATA - high 00DATA - low C8 DATA - low C8CRC - low CE CRC - low CECRC - high DD CRC - high DD
