Specifications - Toshiba TC-net Instruction Manual

1. Outline of OPC Server

1.4. Specifications

The specifications of functions for data access of TC-net scan memory are described below.
Access
Read
Write
Important:
No special security is set for writing to the scan memory of TC-net.
Therefor you must write from OPC Server in consideration of influence on system.
4
Figure 1.4 Specifications of data access
Method
Synchronous read
Asynchronous read
Data change notification
(Subscription)
Synchronous write
Asynchronous write
Description
Reads the scan memory data corresponding to an item.
Waits until reading is completed.
Reads the scan memory data corresponding to an item.
Returns to the original state immediately after a request,
and calls the method on the OPC client side when
reading is completed.
Checks periodically and reports to the OPC client of
changes of scan memory data of a Certain width or
greater.
Writes to the scan memory data. Waits until writing is
completed.
Writes to the scan memory data. Returns to the original
state immediately after a request, and calls the method
on the OPC client side when writing is completed.