BACnet Communications Troubleshooting Procedures

[orion242]

Check the usual dirty cheep electronics sites. These mini handheld scopes are available at disposable prices. Search for pocket oscilloscope. Sure some for the cost are worthwhile.

[kontrolphreak]

What interested me with the Xminilab is the protocol analyzer function.

I've been building a test bench at work with around 30 old controllers that were installed for a decade until recently removed.

Will be able to do more with the test bench, such as change baud rate on controllers and see effect (the stuff I work with now is auto-baud so couldn't manually change one or two), change protocol from BACnet to proprietary, rewire with non-IEA485 wire among other things and see the effects via the different testers and scopes from the opening post.

Would like to spend more time with this (was wiring the controller s till 9pm one day last week after work) but work has been busy with some critical deadlines. I think I'll have some time after next week for a post on the KMC router.

kontrol out

[orion242]

What interested me with the Xminilab is the protocol analyzer function.

Take it there is PC software that goes with it? Would be brutal trying to decode a wad of raw hex on a screen where each character is made up with 5x3 pixel font.

[numbawunfela]

Guys, no pricing in the open forum. Please edit your posts or it will be done for you.

kontrol out

My philosophy is "If you are gonna do something, don't do it halfway"
If I am gonna post prices in the open forum, I will do it in EVERY SINGLE POST"

My apologies, I have been Googling Oscilloscopes and RS485 for days, stumbled onto protocol analysis, was a few days into that rabbit hole, and stumbled across this awesome thread. I didn't even notice it was in the open area.

Kontrolphreak, it is pretty incredible that you went to the hassle of not only finding but acquiring this IF Tools Serial analyzer:
https://www.iftools.com/analyzer/ind...hoCwrwQAvD_BwE

Not only is it only in Europe only, not cheap, but it is an odd thing you will not find may guys toying with. Good work bringing it to the table for the rest of us in Htalk land.

[orion242]

Penn State guy talking about the problems with large BACnet networks with Optigo.

https://www.youtube.com/watch?v=MvbSEfSwxhk

[orion242]

Using a raspi for BACnet/IP capture. This setup is to slip in line, no hub or mirror port required. Onboard nic can be use for remote access and live desktop access with WS. This is setup to power up and capture whatever traffic without any interaction. Its well suited for long term continuous captures with good size SD cards. The capture is also not polluted with traffic from the remote monitor nic. Have a handful of these setup now and find them very useful.

https://buildingsys.net/raspi-network-tap/

If someone wants SD cards pre-loaded with everything setup, PM me. Images are too large for hassle free sharing, but I'll ship SD cards for a minor fee. I'm also working on my own network tap that is better suited for this setup @ half the cost. The GSG tap is a PITA with the cables coming out all four sides. Thinking of a board with male RJ45s that stab directly into the USB nics and just two female ports for the capture in/out connections. Eliminates two patch cords and shrinks the size a fair deal.

[incontrol]

All devices seem normal on their own but everything goes down when hook up. I noticed the A almost flatlines and the A-B is always negative. I tried 4 different adapters. No computer hooked up; just adapters.

plugged


unplugged

[kontrolphreak]

What are you hooking up? Controller? Gateway? IEA485 converter?

Appears whatever it it is pulling the A wire signal to ground.

kontrol out

[incontrol]

I am plugging in my serial to mstp converter which is not even plugged into my laptop.

[orion242]

my serial to mstp converter which is not even plugged into my laptop.

Looks like its hooped then. Try another.

Thinking of a board with male RJ45s that stab directly into the USB nics and just two female ports for the capture in/out connections. Eliminates two patch cords and shrinks the size a fair deal.

From thinking...to using. Way more compact and all the cables exit the same direction.

[incontrol]

Looks like its hooped then.

Does Hooped mean Hosed?
Tried 4 all set the same and been using for years and years.

[orion242]

Assuming so with the info at hand. Wouldn't expect it to cause any disruption to the trunk by simply connecting it. That guy looks to be shorting one leg out when connected. Discussion for another thread.

[Chipkin]

Hey guys,

I'm new to the group, but I just wanted to share TWO new BACnet Tools for Wireshark we created. They're great for troubleshooting and both free to download and use.

The forum won't allow me to post links, but you can search for them on Google or PM me and I'll give you the link. They are the "CAS BACnet Wireshark Report Tool" and "CAS BACnet Wireshark Storm".

CAS BACnet Wireshark Report Tool

CAS BACnet Wireshark Storm

[kontrolphreak]

Welcome to the forum Peter. I took the liberty to add hotlinks to your post.

kontrol out

[Chipkin]

Welcome to the forum Peter. I took the liberty to add hotlinks to your post.

Thank you very much For the welcome and the links.

[orion242]

These look very nice. Thanks Peter.

[ddcfan]

I've been MIA for some time and I returned today to find this thread....This is a fantastic thread!!! Several yrs back, I was at a site with 13 major buildings and 2 research facilities and all were very sick buildings. After taking time in fixing polarity, grounding, star, length, shielding, wrong placement of terminators and noise issues, the networks were somewhat stabilized but it wasn't until I pulled out the oscilloscope did the contractor believe me that he had some bad issues with his installed network. His response.... those oscilloscope captures done at the factory are done in controlled perfect factory environments...they are not effective in real life...

uh...hello?

lol..thought I share a funny irony

Great job fellr's!

[stanbyyourword]

I had the most luck with Chipkin Modbus tool , so I know their stuff is solid

[orion242]

Another tool to have in your toolbag of tricks is the IF Tools msb-rs485 Serial Interface Analyzer. I feel it is a jack of all trades but a but haven't used it as much as an oscilloscope and Wirehark.

Just to add my two pennies on this device...

One big downfall is not being able to export to pcap file and dissect in wireshark. Included decode is pretty limited. If you need precise 485 timing analysis, this is the tool. If your looking for a device that can do precise timing and full decode, its not for you unless you want to write your own decoder/exporter which is certainly possible. Somewhat surprised they don't export to pcap for the price as it would certainly add to the value and be an easy out for R&D.

Its a great tool, just be aware it mainly for timing / LA type work and not what most would require for 95%+ problems in the field. By the time you need to whip this out, you have well advanced knowledge of the protocol at hand.

[numbawunfela]

Hey guys,

I'm new to the group, but I just wanted to share
"CAS BACnet Wireshark Storm".

CAS BACnet Wireshark Storm

The description on the site:
Download Now and Replay BACnet client messages, directing them to a new IP so you can replicate a site problem where the server could not handle an incoming request properly. Test and simulate message storms and DOS attacks.

We have a site that is a fun Niagara/Distech (on an old N2 18/3 trunk)/Schneider BACNet/Infinet mix. The kind of place where you know something bad will probably happen as you stumble across the messes someone knows about but will not tell you is there until you are on a proposal job.

We will be doing work with a few guys who are newer, I may have to mess with somebody in the name of science when I test this one out.