Host Engineering Forum

General Category => General Discussion => Topic started by: inanaz on September 11, 2019, 05:30:28 AM

Title: VPN Question - Not Restricted to PLCs
Post by: inanaz on September 11, 2019, 05:30:28 AM
When online with a Do-more at our office from home via VPN, the Trend View, PID View and Data View all show a hesitation of approximately 1.53 seconds occurring around 5.5 second intervals. The duration tends to be pretty consistent, the recurrence is less so but regular and always.

I also see this with another device on the same network which is not a PLC but does have a trending display in its software package.

The devices are not hesitating, it is just the update in the views of the data. This happens with different computers also.

I am not a network person by any means which also means I don't really know how to phrase a query to get useful results from a search engine.

Does anyone have any ideas where I need to start looking to at least minimize this? The trend view screen capture below is very typical of what I see.
Title: Re: VPN Question - Not Restricted to PLCs
Post by: ADC Product Engineer on September 11, 2019, 08:21:50 AM
Could be anything really.  Most likely it is from your ISP although it could be security software, your router, your modem, the site modem, the site router or something on one of the networks that is burping big quantities of data at a fairly regular interval.

Internet communications is a deep well.  There are so many variables without more information it would be very difficult to pin down what is happening.

If it were me, I would start by complaining to your ISP and see if they can help. 
Title: Re: VPN Question - Not Restricted to PLCs
Post by: Mike Nash on September 11, 2019, 12:16:29 PM
I get that too. Pretty irritating. I have managed to get a slightly more acceptable result by changing the timeout and retries in the Link configuration in Do-more Designer. Sometimes it means more frequent, but shorter duration pauses, and I have had to juggle the values differently at different times.
Title: Re: VPN Question - Not Restricted to PLCs
Post by: Controls Guy on September 24, 2019, 08:18:27 PM
These two trends are over a VPN using a link I use all the time directly connected.  I don't think any special settings.

The ~900ms recycling timer seems to consistently get about 4-6 updates per cycle with no burps, and the $now.second trace looks fine.

My bandwidth at the shop is about 11 down, 3 up, and the site is excellent at about 98 down, 15 up.
Title: Re: VPN Question - Not Restricted to PLCs
Post by: Mike Nash on September 26, 2019, 10:08:27 PM
Yes that does look nice. I was never able to determine where the timeout was being caused, but the VPN was to our office and who knows whether it was the router gremlins or the horrible internet service we have there.