COMMUNICATIONS GUIDE
MODBUS FUNCTIONS
469 MOTOR MANAGEMENT RELAY – COMMUNICATIONS GUIDE
11
MESSAGE FORMAT AND EXAMPLE:
Request slave 11 to store the value 01F4 to setpoint address 1180 and the value 01DE to
setpoint address 1181. After the transmission in this example is complete, 469 slave 11 will
have the following Setpoints information stored:
Performing Commands
Some PLCs may not support execution of commands using function code 5 but do support
storing multiple setpoints using function code 16. To perform this operation using function
code 16 (10H), a certain sequence of commands must be written at the same time to the
469. The sequence consists of: command function register, command operation register
and command data (if required). The command function register must be written with the
value of 5 indicating an execute operation is requested. The command operation register
must then be written with a valid command operation number from the list of commands
shown in the memory map. The command data registers must be written with valid data if
the command operation requires data. The selected command will execute immediately
upon receipt of a valid transmission.
Address
Data
1180
01F4
1181
01DE
Master Transmission
Bytes
Example
Description
Slave Address
1
0B
message for slave 11
Function Code
1
10
store multiple setpoint value
Data Starting Address
2
11 80
data starting at 1180h
Number of Setpoints
2
00 02
2 setpoints = 4 bytes total
Byte Count
1
04
4 bytes of data
Data #1
2
01 F4
data for address 1180h
Data #2
2
01 DE
data for address 1181h
CRC (low, high)
2
DB B1
computed CRC error code
Slave Response
Bytes
Example
Description
Slave Address
1
0B
message from slave 11
Function Code
1
10
store multiple setpoint value
Data Starting Address
2
11 80
data starting at 1180h
Number of Setpoints
2
00 02
2 setpoints = 4 bytes total
CRC (low, high)
2
45 B6
computed CRC error code
