Knowledge Base

Why does the time-out message 6208 or 3410 only appear on some NS COM variables ?

The time-out is applied to a packet of variables – the size of the packet is defined by the PacketSize parameter in OPTION.DAT.
For each packet only the first 10 variables, which do not have a subscription response, generate a time-out message in the Event Viewer and TRACE.LOG.

What is the Timeout parameter in OPTION.DAT used for?

[WATCHVARS\EXT]
PacketSize=500
TimeoutEnable=1
Timeout=20

It is the maximum time to wait for the subscription response for each variable in a packet before generating an error message and proceeding to the next packet.

Exactly how is Timeout used?

In the file C\LANCONF.DAT, under the section [WATCHOBJS], there is a parameter MultipleOfTODuringStarting with a default value of 5.
This parameter is used to increase the time-out for subscription response during certain phases. During these phases the actual time-out = Timeout * MultipleOfTODuringStarting. This parameter is used in the following phases.
1.      During the starting of PcVue
2.      For DelayBeforeStartWatchOnActiveStandby after PcVue startup is complete. DelayBeforeStartWatchOnActiveStandby is also found in the section [WATCHOBJS]. The default value is 600 seconds.
Example: If the parameters are set to the default of Timeout = 20 and MultipleOfTODuringStarting = 5, during these two phases the time-out is 20 * 5 = 100s

Why do we need to multiply Timeout?

Because during the starting phase there may be a lot of traffic on the network particularly if there are many data acquisition servers.
The minimum value of MultipleOfTODuringStarting is 1.

What is the total subscription time on startup if there is a time-out on every packet?

Total subscription time =  (number of subscribed variables / PacketSize) * (Timeout * MultipleOfTODuringStarting)