Micromod MOD: Extended Modbus (XModbus) OPC Server Users Guide - Manual (Page 4)

Training Manual
Introduction
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1.2.2 Extended Modbus Protocol
Modcell and MOD30ML devices support an extended protocol, in addition to standard
MODBUS RTU. XModbus OPC Server supports these extended features allowing
additional data types, automatic scaling and entry of user defined tag names. The extended
protocol also supports ViZapp Debug and Status displays, which may be used to provide
extended diagnostic and event information. Note that the 2-wire RS-485 module does not
support these features.
When using Extended MODBUS, special interface files are created when compiling the
instrument database. These files provide automatic configuration of host poll records,
significantly reducing engineering time. A MIF file is used for XModbus OPC Server and
FIX software. PC-30 and GFW use a TIF file. With Extended MODBUS, user-friendly
alias names are given to points in the Configured List. In the host software, these alias
names are used instead of register addresses.
1.2.3 Built-in OPC Client
An OPC Client application is built-in with the Extended Modbus OPC Server for
monitoring and testing your Server’s configuration. It is this part of the OPC application
that collects data received by the OPC Server and presents to the user. The data
presented by the OPC Client is live.
OPC Client is useful for testing the communication between the devices and the OPC
Server. It can also be used for testing other 3rd party OPC applications connected to the
server.