Technical data

83
W&T
Subject to errors and modifications
If there is a need to eliminate an undesirably high network load,
the OPC client would be the first place to start. There you could
select any unnecessarily high update rate and choose not to
subscribe to any OPC items which are not really essential. If
this does not help (or if the behavior of the OPC client cannot
be modified in these ways), a lower limit for the time between
read accesses can be specified in the OPC server. The default
is 100ms, but depending on the device type a significantly
greater lower limit can be chosen. For example would be the
typically change of measurements of temperature very slowly.
For some types of OPC items (Example: the inputs on the Web-
IO Analog) the device itself reports all changes, so that the OPC
server does not need to perform any explicit read operations.
But it does exactly that from time to time, namely in order to
obtain a life sign from the device, since otherwise connection
dropouts would not be reliably detected. The upper limit for the
time interval between read accesses determines how often (at
minimum) this occurs.
Processing multiple devices: You can also edit the timing
parameters for multiple devices at the same time. In dialog
fields whose content is not the same for all selected devices, a
tilde („~“) is displayed. Fields in which the tilde remains even
when closing the dialog field retain their various contents.