Vortice VORT NRG 600 EC Manuel D'utilisation Et De Mise En Marche page 48

ENGLISH
Modbus Connection
The Modbus protocol consists of several layers (OSI model). The bottom layer is the physical layer, and is comprised of
a number of wires and signal levels. The next layer describes the communication digits (number of data bits, stop-bits,
parity, etc). Next are the layers describing the specific functions of the Modbus protocol (number of digits per message,
the meanings of different messages, etc).
For Modbus, the physical layer can be RS485, RS422 or RS232.
Example
The simplified example below illustrates the master-slave relationship. In addition, checksums for message validation are
also transmitted in both query and answer.
Computer running a Modbus master application
Query:
"Read from point
address x on Slave
address 2"
Configuration
The first important things to configure are the communication parameters for the Modbus line. As described earlier, these
parameters must be identical in the master unit and the slave units, since they define the structure of messages and the
transmission speed.
The default configuration values of a Corrigo E controller are shown in the figure below.
Corrigo E is by default set to Slave Address 1. For each other unit added, a new Modbus address can be set using the
Corrigo E display or E tool.
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Corrigo E
Slave Address: 1
Modbus/RTU
9600 baud
Parity: none
2 stop bits
Answer:
"Slave address 2 contains
value z on requested point
address"
Corrigo E
Slave Address: 2
Modbus/RTU
9600 baud
Parity: none
2 stop bits