socomec COUNTIS E03 - 8. COMMUNICATION; 8.1. Modbus Communication Overview; 8.2. RS485 Network Guidelines

12 EN
COUNTIS E03/E04 - 545865A - SOCOMEC
8. COMMUNICATION
8.1. General information
The Modbus communication available on the COUNTIS E03/04 communicates via an RS485 series link (2 or 3 wires)
which is used to operate devices from a PC or an API.
In a standard conguration, an RS485 connection is used to connect 32 products to a PC or a controller over 1200
metres.
+ - NC
N 1
+ - NC
N 2
+ - NC
N n
+ - NC
N 1
+ - NC NC - + + - NC
N n
Programmable
machines
Programmable
machines
Other systems
Other systems
Repeater
8.2. RS485 rules
A LIYCY shielded twisted pair must be used. We recommend using a shielded twisted pair with a general LIYCY-CY
shielding in an environment where there is interference or in a very long network with a number of products.
If the distance of 1,200 m is exceeded and/or the number of products is greater than 32, a repeater must be added
to enable additional products to be connected.
A 120 Ohm resistor must be xed at both ends of the connection.