Lost comms with outstation on channel XX in GEO SCADA

[BGedco2022]

Hello,

"Lost comms with outstation on channel XX"

our client, issue a repeated behavior around specific hour every day!!!, where most the outstations lost comm. and establish it again in seconds repeatedly as noticed in the events journal at GEO SCADA while they were really connected after checking.

We have traced their drivers log (modbus and dnp3) nothing found  except  shows similar messages to the events log

What could causes such behavior? and how to prevent it?

Appreciate any suggestions /hints.

Thanks in advance.

[sbeadle]

Hi,

You could enable comms logging on the channel to see what's happening at the time. Either a poll (or a number of them) are going unanswered by the device, or perhaps some noise is returned.

It might be that the driver is waiting for a server response and misses a reply, but if that's the case you may see the replies later in the log.

Steve

[BGedco2022]

Thanks Steve

We did enable Comms Logging on a sample and we will see>>>

But to give you more clear picture as below of the event journal of an outstation:

as you see the comms keeps lost and established in less than second between each event

Is it possible of missing or wrong configs at channel level or outstation level?

Thanks again 

[BevanWeiss]

I've seen similar behaviour in a few situations.

• A DNP3 device firmware bug that caused it to swap the active route to the backup channel when it received a Shared Outstation Channel heartbeat.  It caused ClearSCADA to fail over channels, and then the same behaviour would occur on that channel.
• Poorly configured firewall rule that allowed the Establishment messages (for TCP) but not Connected messages (i.e. the actual traffic).

Does your client have an RTU that is directly adjacent to their GeoSCADA server (i.e. that wouldn't be prone to network issues)?

Are there outstations that don't have this same behaviour?

Does the timing coincide with anything else, like network operations, large backups elsewhere, backups on the GeoSCADA Expert servers etc?