EVCO EPU2LXP1CH - Manual (Page 17)

EVCO S.p.A. c-pro 3 micro and c-pro 3 kilo | Hardware manual ver. 1.0 | Code 114CP3UKE104
page 17 of 62
RS-485 port
RS-485 port with Modbus master communication protocol (with network already polarized internally).
Terminal Meaning
GND ground
A / + terminal 1 of the transceiver
B / - terminal 0 of the transceiver
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”.
Termination RS-485 port
Micro-switch to plug in the termination of the RS-485 port with Modbus master communication protocol (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).