Modbus Opc Server Features - ABB COM600S User Manual

1MRS756445
2.3.
COM600 series, Version 4.1
Modbus TCP Master (OPC) User's Manual
Figure 2.2-1 Modbus system overview
(1) NCC (Network Control Center)
(2) COM600 with Modbus OPC Server
(3) Station Automation Builder 600 (SAB600)
(4) Protection and control devices communicating through the Modbus protocol
To create a common and protocol independent data interface between the OPC server
and client, the process data from the devices is remodeled using the IEC 61850 data
modeling.
The configuration data is stored in the SCL format. After the OPC Server has been
launched, it reads the configuration file and establishes communication with the devices
through the protocol stack.
Configured devices and data modeled according to the IEC 61850 model (see
5.2.1, General about IEC 61850 data modeling) are then exposed to OPC clients through
a Data Access (DA) server.

Modbus OPC Server features

The Modbus OPC Server is intended for connecting simple Modbus devices like energy
meters and input/ouput modules. As the protocol is based on scanning the state of the
inputs of the device, it depends on the scan rate how short signal transients are registered.
No events or time stamps are supported.
The Modbus messaging service provides a client/server communication between devices
connected on an Ethernet TCP/IP network. This model is based on four types of messages:
request, confirmation, indication, and response.
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