Read Device Status - GE 469 Communications Manual

COMMUNICATIONS GUIDE

Read Device Status

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