Multilin SR469 - Function Code 16 - Performing Commands

6. COMMUNICATIONS SUPPORTED MODBUS FUNCTIONS
6-13
6.3.9 FUNCTION CODE 16 - 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
SR469. 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 Com-
mand Data registers must be written with valid data if the command operation requires data. The selected command will execute imme-
diately upon receipt of a valid transmission.
Message Format and Example:
Perform a reset on SR469 (operation code 1).
Master Transmission Bytes Example (hex)
SLAVE ADDRESS 1 0B message for slave 11
FUNCTION CODE 1 10 store Setpoints
DATA STARTING ADDRESS 2 00 Setpoint address 0080
80
NUMBER OF SETPOINTS 2 00 2 Setpoints (4 bytes total)
02
BYTE COUNT 1 04 4 bytes of data
COMMAND FUNCTION 2 00 data for address 0080
05
COMMAND OPERATION 2 00 data for address 0081
01
CRC 2 0B CRC calculated by the master
D6
Slave Response
SLAVE ADDRESS 1 0B message from slave 11
FUNCTION CODE 1 10 store Setpoints
DATA STARTING ADDRESS 2 00 Setpoint address 0080
80
NUMBER OF SETPOINTS 2 00 2 setpoints
02
CRC 2 40 CRC calculated by the slave
8A