Siemens SENTRON PAC3120, Manual, Page: 113 / 160

PAC3120 and PAC3220
Equipment Manual, 10/2019,
L1V30425208F-01
111
Appendix
A
A.1 Modbus
Detailed information about Modbus can be found at the Modbus website
( http://www.modbus.org ).
A.1.1 Function codes
Function codes control the data exchange. To do this, a function code tells the slave which
action it is to take.
If an error occurs, the MSB bit is set in the response frame in the FC byte.
Supported Modbus function codes
Table A- 1 Supported Modbus function codes
FC Function in accordance with Modbus specification
0 x 01 Read Coils
0 x 02 Read Discrete Inputs
0 x 03 Read Holding Registers
0 x 04 Read Input Registers
0 x 05 Write Single Coil
0 x 06 Write Single Register
0 x 0F Write Multiple Coils
0 x 10 Write Multiple Registers
0 x 2B Read Device Identification
0 x 14 Read File Record (for demand values)