Toshiba TC-net 100 - 1.4. Data Access Specifications

1. Outline of OPC Server
4
1.4. Specifications
The specifications of functions for data access of TC-net scan memory are described below.
Figure 1.4 Specifications of data access
Access
Method
Description
Read
Synchronous read
Reads the scan memory data corresponding to an item.
Waits until reading is completed.
Asynchronous read 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.
Data change notification
(Subscription)
Checks periodically and reports to the OPC client of
changes of scan memory data of a Certain width or
greater.
Write
Synchronous write
Writes to the scan memory data. Waits until writing is
completed.
Asynchronous write
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.
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.