socomec COUNTIS E23 Operating Instructions

7
COUNTIS E23/E24 - Ref.: 542 102 A
COUNTIS E23/E24 MODBUS
6. MODBUS communication
6.1. General Information
MODBUS
®
communication is performed via a RS485 serial port (2- or 3-wire) which enables products to be used
from a PC or an API.
Onastandardconguration,aRS485portcanbeusedtoconnect32productstoaPCoraPLCacross1200
meters.
R=120Ω
R=120Ω
R=120Ω
R=120Ω R=120Ω R=120Ω
R=120Ω
R=120Ω
R=120Ω
R=120Ω R=120Ω R=120Ω
MODBUS wiring
Wiring with repeater
≈1200mor32UL
≈1200mor32UL ≈1200mor32UL
Repeater
0 -> NC
0 -> NC
6.2. Recommendations
It is necessary to use a shielded twisted pair (LIYCY type). In an environment where there is interference or large
network (in terms of length) we recommend the use of a shielded twisted pair (type LIYCY-CY).
A repeater should be used to connect additional products if the distance of 1200 m and/or maximum number of 32
products is exceeded.
A120-ohmresistormustbexedatbothendsofthelink.
6.3. Communication structure
The product communicates via a MODBUS
®
protocol, which involves a dialogue using a master-slave structure. The
mode of communication is the RTU (Remote Terminal Unit) mode using hexadecimal characters of at least 8 bits.
MODBUS
®
frame structure (master -> slave exchange):
Slave address Function code Address Number of words to read CRC 16
1 byte 1 byte 2 bytes 2 bytes 2 bytes
6.4. Communication table
The communication tables and associated explanations are
available on the COUNTIS E23/E24 documentation page online at
the following address:
www.socomec.com/en/countis-e2x

socomec COUNTIS E23 Specifications

General

Brand	socomec
Model	COUNTIS E23
Category	Measuring Instruments
Language	English