GE Power Management
469 Motor Management Relay
6-5
6 COMMUNICATIONS
6.2 SUPPORTED MODBUS FUNCTIONS
6
c) MESSAGE FORMAT AND EXAMPLE, FUNCTION 01
Request slave 11 to respond with status of relay coil 3 to 5:
If STARTING RELAY COIL (STARTING DIGITAL INPUT) of Zero is entered, then 469 will default it to
One. If the NUMBER OF RELAYS (NUMBER OF DIGITAL INPUTS) requested exceeds the number
of relays available then user is prompted with a “ILLEGAL DATA” message.
Relay
Status
R1
Energized
R2
De-energized
R3
De-energized
R4
De-energized
R5
Energized
R6
Energized
Bit Mask
0011 0001 (0 x 31)
MASTER TRANSMISSION:
BYTES
EXAMPLE / DESCRIPTION
SLAVE ADDRESS
1
0B
message for slave 11
FUNCTION CODE
1
01
read relay coil status
STARTING RELAY COIL
2
00 03
starting relay coil 3
NUMBER OF RELYAS
2
00 03
3 relays coils (i.e. R3, R4, R5)
CRC
2
8C A1
CRC calculated by the master
SLAVE RESPONSE:
BYTES
EXAMPLE / DESCRIPTION
SLAVE ADDRESS
1
0B
response message from slave 11
FUNCTION CODE
1
01
read relay coil status
BYTE COUNT
1
01
1 byte bit mask
BIT MASK
1
10
bit mask of requested relay (0001 0000)
CRC
2
53 93
CRC calculated by the slave
NOTE