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CHAPTER 1: COMMUNICATIONS GUIDE
Function Code 06H
Function Code 07H
345 TRANSFORMER PROTECTION SYSTEM – COMMUNICATIONS GUIDE
The commands that can be performed by the 345 using function code 05 can also be
initiated by using function code 10.
Operation Code
1
4
5
96
97
99
100
102
Modbus Implementation: Preset Single Register
345 Implementation: Store Single Setpoint
This command allows the master to store a single setpoint into the memory of a 345 The
slave response to this function code is to echo the entire master transmission.
For example, request slave 17 to store the value 2 in setpoint address 04 5C. After the
transmission in this example is complete, setpoints address 04 5C will contain the value
01F4. The master/slave packet format is shown below:
Table 36: MASTER/SLAVE PACKET FORMAT FOR FUNCTION CODE 06H
MASTER TRANSMISSION
SLAVE ADDRESS
FUNCTION CODE
DATA STARTING ADDRESS
DATA
CRC
SLAVE RESPONSE
SLAVE ADDRESS
FUNCTION CODE
DATA STARTING ADDRESS
DATA
CRC
Modbus Implementation: Read Exception Status
345 Implementation: Read Device Status
This is a function used to quickly read the status of a selected device. A short message
length allows for rapid reading of status. The status byte returned will have individual bits
set to 1 or 0 depending on the status of the slave device. For this example, consider the
following 345 general status byte:
Description
Reset
Open
Close
Close Last Trip Data Prompt
Reset MWh and Mvarh Meters
Clear Counters
Clear Event Records
Clear Maintenance Info
BYTES
EXAMPLE
1
11
1
06
2
04 5C
2
00 02
2
CB B9
BYTES
EXAMPLE
1
11
1
06
2
04 5C
2
00 02
2
CB B9
MODBUS FUNCTIONS
DESCRIPTION
message for slave 17
store single setpoint
setpoint address 04
5C
data for setpoint
address 04 5C
CRC error code
DESCRIPTION
message from slave
17
store single setpoint
setpoint address 04
5C
data stored in
setpoint address 04
5C
CRC error code
1–173
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