COMMUNICATIONS GUIDE MODBUS FUNCTIONS
469 MOTOR MANAGEMENT RELAY – COMMUNICATIONS GUIDE 9
Read Device Status
Modbus Implementation: Read Exception Status
469 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.
469 General Status Byte:
If status is neither stopped or running, the motor is starting or has been tripped.
Master Transmission Bytes Example Description
Slave Address 1 0B message for slave 11
Function Code 1 06 store single setpoint
Data Starting Address 2 11 80 data starting at 1180h
Data 2 01 F4 data for address 1180h
CRC (low, high) 2 8D A3 computed CRC error code
Slave Response Bytes Example Description
Slave Address 1 0B message from slave 11
Function Code 1 06 store single setpoint value
Data Starting Address 2 11 80 data starting at 1180h
Data 2 01 F4 data from address 1180h
CRC (low, high) 2 8D A3 computed CRC error code
Bit Description Bit Description
B0 1 TRIP relay operated = 1 B4 5 BLOCK START relay operated = 1
B1 2 AUXILIARY relay operated = 1 B5 6 SERVICE relay operated = 1
B2 3 AUXILIARY relay operated = 1 B6 Stopped = 1
B3 4 ALARM relay operated = 1 B7 Running = 1
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