Specifications

A - 14 RSLinx – Training Guide
Understanding How RSView32 Manages
Communications With RSLinx - or Any DDE/OPC
Server.
The information in this technote applies to:
Product:
RSView32
Type:
Application Note
Technote ID:
A951
Package/Mod
ule(s):
Runtime
Works
Modified:
12/15/98
Revision(s):
6.00.41
Fixed In
Revision:
Sub-
System(s):
RSLinx
Technical Note Details:
Background:
RSView32 has implemented a very sophisticated mechanism for only requesting
the data that is needed from the data server. This means that as screens change
in the HMI, RSView32 asks the data server for different data. When RSView32 is
asking RSLinx for DDE or OPC data, then the Active Items list can be viewed to
determine exactly what RSView32 is asking RSLinx for. When RSView32 is
asking RSLinx for Direct or C-API data, then the Active Items list does not show
the data being requested.
Understanding how RSView32 asks the data server for data is important when
optimizing communications, and when implementing unsolicited message data,
which is data that originates from the PLC, or data not being polled by the HMI.