Can not connect via BACnet to T3-NANO

I recently purchased a T3-NANO. I just can not talk to it via BACnet. When I connect to my PC directly I can not scan the T3-NANO IP address. When connecting through the router I can see T3-NANO but it comes up with an error "No Bacnet “Who is?” then it pops up with the label T3-XB-ESP but it struggles to communicate.

Also I have a strong feeling that the IP comms. are MODBUS/IP and not BACnet/IP, but I might be wrong

Please help…

Also an additional printscreen of the searched devices using both COM3 and Ethernet. The ethernet port shows 502 instead of 47808 which might also indicate that T3-NANO is MODBUS/IP instead of BACnet /IP

Anyone’s help is much appreciated.

Could we first show a couple of screen shots from T3000, including the network settings screens. And next step go to T3000 → tools → Bacnet tool and show us what you see there. Once you have that working we can move on to your particular Bacnet tool.

Search this forum for some screen shots of the T3000 Bacnet tool, its mainly the open source Bacnet tool called ‘Yabe’ there.

The screen shot shows the connection health is not very good. I would sort this out before moving on to other bacnet tools. You should be able to see all the inputs, outputs and so on in T3000.

If you cannot get this work work you can search around with keywords network, IP, DHCP and so on.

Show us a few screen shots like below and perhaps we can see something.

Only when you have the inputs, outputs, etc showing up well then move on to testing with the T3000 → tools → Bacnet tool to work with bacnet objects.

Also you can check these things to see if you are really online:
Tab1 shows an offline device. ( x near the device in the tree)
Tab2 shows the currently selected and online device. (red name, no x in the tree)
Tab3 shows a ‘virtual device’ which is also offline. ( greyed out name, also x in the tree)
Tab4 shows the inputs for the currently selected device at Tab2.


Hi Maurice,

Please see all the printscreens. BACnet object don’t even show up in Yabe. Just one which is AV129. It’s almost as if this device don’t have any BACnet objects available in its database.
Kindly awaiting response



You are attempting a remote connection to another system on a different subnet. You should start with a simple test, connect directly from your PC to a device on your local lan. Once you have that working you will see all the inputs, vars, outputs and so on in T3000 like I show above at Tab4. In your case you see a grey box, data is not getting through.

Once you have the basics working on a local lan you can test your bacnet objects locally.

Once you have that going we can move on up to testing remote systems.

Hi Maurice,

When connecting my PC directly to the T3-NANO I can not see it or ping it. My PC can not see it without connecting to the router.

Also when iam connecting my PC to a netgear switch (not the router just the switch) I also can not see or ping T3-NANO.

I have run Advanced IP scanner to try and find T3-NANO IP address but to no avail. It is only when T3-NANO is connected to the router that its IP address pops up.

What IP address does T3-NANO have when not connected to the router? Does it possibly default to its original IP address. If it does what would that IP address be?

Thanks Maurice

Direct connection: This will depend on your PC/Laptop. If it has auto negotiation it can handle a direct cable link. If it doesnt then it will need a hub or router in between the two.

Ping: This is the most basic test, if you cannot see a device with Ping there is some sort of routing/IP issue.

Advanced IP Scanner: It would help to see a wireshark capture with your tool, maybe we can see something there.

Default IP address: When we test them in the office they are on 192.168.0.XXX and DHCP is enabled.

If you dont have a DHCP server the device will fall back to the last known good IP address

If the device has picked up an address at any point during your testing it would fall back to that.

If the device has not picked up an address since it left our test site it would default back to that.

Thanks Maurice. I will do the wireshark capture. Specifically, what do you want me to write in the Wireshark Command line.

Hi Maurice,

Wire shark capture enclosed for your convenience.

T3-NANO-Wireshark Capture.pcapng (524 Bytes)

Thanks for fixing the issue Gents

Fandu explained to me that there were some settings from the assembly/test folks at our factory that were causing problems. Apologies for that and standing by to help if there are any more issues.

Yes FanDu was great thank you.
I have another issue though. I can not BACnet Read/Write to and from a third party device.
I also can not Read/Write from T3-NANO either.
When discovering T3-NANO with Yabe I noticed that no BACnet points get populated at all.
It is imperative that I have the ability to integrate T3-NANO into the third party devices.
Please see printscreens below. Your help would be greatly appreciated as always…

Search this forum for ‘network programming’ and also ‘priority array’. Start a new thread if something comes up on either of those two topics.