Glossary - Seneca Z-KEY User Manual

1. Glossary


Modbus RTU
An open protocol for the serial communications developed by Modicon Inc. (AEG Schneider Automation
International S.A.S.). Simple and robust, it has since become a de facto standard communication protocol.
For more info http://www.modbus.org/specs.php

MODBUS TCP-IP
The Modbus RTU protocol with a TCP interface that runs on Ethernet.
For more info http://www.modbus.org/specs.php

MODBUS BRIDGE
A device that translates, in real time, from Modbus TCP-IP ethernet protocol to Modbus RTU serial
protocol.

MODBUS GATEWAY
A device that translate Modbus TCP-IP protocol to Modbus RTU protocol using a buffered memory (called
shared memory). The shared memory can be accessed by multiple devices through Modbus TCP-IP,
Modbus RTU, Webservers etc... but must be configured. The Modbus Gateways are used for speed-up and
for simplify a Modbus network.

SERIAL DEVICE SERVER (REMOTE COM PORT)
A device that enables devices with an RS-232, RS-422 or RS-485 serial interface to connect to an IP network.
This makes it possible to use Ethernet in place of serial cables, minimizing workstation clutter and also
allowing serial devices to be placed far away from the computers with which they are used. A Serial device
server is virtually transparent to the serial protocol.

MODBUS RTU MASTER-SLAVE
The Master is connected with one or more slaves, the slave waits for an incoming register(s) request from
the master. Only one master is allowed, for overcome this limitation you must use a Modbus gateway.

MODBUS TCP-IP CLIENT-SERVER
USER MANUAL – Z-KEY
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