FUNCTION CODE 42H
Function Code 42H
Function Code 43H
8-14
Modbus Implementation: (not a standard function)
3 Series relay Implementation: Read Settings Group
All protection functions for the 345 and 350 relays have two sets of settings - Group 1 and
Group 2. This function number is used to read the settings for each group. (This function
does not apply to the 339 relay.)
Example:
Field Name
Slave Address
Function
Group Activation
Starting Address Hi
Starting Address Lo
No. of Registers Hi
No. of Registers Lo
Response:
Field Name
Slave Address
Function
Byte Count
Data Hi
Data Lo
Modbus Implementation: (not a standard function)
3 Series relay Implementation: Write Settings Group
All protection functions for the 345 and 350 relays have two sets of settings - Group 1 and
Group 2. This function is used to write settings in a specific settings group. (This function
does not apply to the 339 relay.)
Example: (In the example there is a write setting procedure in the Group 1 (00), setting
address 0x09C1 and 2 bytes of data with value 0x0001.)
Field Name
Slave Address
Function
Group Activation
Starting Address Hi
Starting Address Lo
No. of Registers Hi
No. of Registers Lo
Hex
FE
42
00
0A
B3
00
01
Hex
FE
42
02
00
00
Hex
FE
43
00
09
C1
00
01
SR3 SERIES PROTECTIVE RELAY PLATFORM – COMMUNICATIONS GUIDE
CHAPTER 8: MODBUS FUNCTIONS