EVCO S.p.A. c-pro 3 | Hardware manual ver. 2.0 | Code 114CP3E204
page 15 of 86
8 not connected
The maximum length of the connecting cables of the RS-485 port is 1,000 m (3,280 ft); also look at the Modbus specifications
and implementation guides manual (the document is available on the internet site www.modbus.org).
Connect the RS-485 port using a twisted pair.
The following table shows the function codes supported by the controller.
Function
code
Meaning
FC 01 read coils
FC 02 read discrete inputs
FC 03 read multiple registers
FC 04 read input registers
FC 05 write single coil
FC 06 write single register
FC 08 diagnostic
FC 15 write multiple coils
FC 16 write multiple registers
FC 23 read write multiple registers
For the settings about the RS-485 port look at chapter 6 “CONFIGURATION”.
MICRO-SWITCH
Micro-switch to:
- plug in the termination of the RS-485 port (120 Ω, 0.25 W); position micro-switch 1 on position ON to plug in the termination of
the RS-485 port (plug in the termination of the first and of the last element of the network)