Execute Operation (Function Code 05H); Store Single Setting (Function Code 06H) - GE B30 Communications Manual

CHAPTER 2: MODBUS COMMUNICATION
Master transmission
Packet format
NUMBER OF REGISTERS - high
NUMBER OF REGISTERS - low
CRC - low
CRC - high

2.2.3 Execute operation (function code 05h)

This function code allows the master to perform various operations in the relay. Available operations are shown in the
summary table below.
The following table shows the format of the master and slave packets in Modbus RTU. Modbus TCP/IP ADUs have a MBAP
instead of slave address, and CRC is in another stack layer. The example shows a master device requesting the slave
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.
Table 2-6: Master and slave device packet transmission example
Master transmission
Packet format
SLAVE ADDRESS
FUNCTION CODE
OPERATION CODE - high
OPERATION CODE - low
CODE VALUE - high
CODE VALUE - low
CRC - low
CRC - high
Table 2-7: Summary of operation codes for function 05h
Operation code Definition
(Hex)
0000 NO OPERATION
0001 RESET
0005 CLEAR EVENT RECORDS
0006 CLEAR OSCILLOGRAPHY
1000 to 103F VIRTUAL IN 1 to 64 ON/OFF

2.2.4 Store single setting (function code 06h)

This function code allows the master to modify the contents of a single setting register in an relay. The following table
shows the format of the master and slave packets in Modbus RTU. Modbus TCP/IP ADUs have a MBAP instead of slave
address, and CRC is in another stack layer. The example shows a master device storing the value 200 at memory map
address 4051h to slave device 11h (17 dec).
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Slave response
Example (Hex) Packet format
00 DATA #1 - low
03 DATA #2 - high
A7 DATA #2 - low
4A DATA #3 - high
DATA #3 - low
CRC - low
CRC - high
Slave response
Example (Hex) Packet format
11 SLAVE ADDRESS
05 FUNCTION CODE
00 OPERATION CODE - high
01 OPERATION CODE - low
FF CODE VALUE - high
00 CODE VALUE - low
DF CRC - low
6A CRC - high
Description
Does not do anything
Performs the same function as the
Performs the same function as the
command
Clears all oscillography records
Sets the states of Virtual Inputs 1 to 64 either "ON" or "OFF"
MODBUS FUNCTION CODES
Example (Hex)
28
01
2C
00
00
0D
60
Example (Hex)
11
05
00
01
FF
00
DF
6A
front panel RESET key
front panel CLEAR EVENT RECORDS menu
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