EVCO EPH4EXP Hardware manual User Manual
Page 18

EVCO S.p.A.
c-pro 3 | Hardware manual ver. 3.2 | Codice 114CP3E324
page 18 of 116
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)