NET2 acu not responding and going off line/on line.

[mickiete]

Hi all,

 

I have 15 of Net2 Classic units on site, using Net2 Pro v6, they are wired in a daisy and end up connected to a Ethernet adaptor.

 

They have all been working fine until Friday when I went to add a card and noticed in the events log just 1 ACU showing "ACU not responding then ACU online" every 2-3 minutes.

When I checked the doors, I noticed 8 units are showing "not responding" with the red X.

 

I have been in the config ip tab and clicked "detect" but it only detects the Ethernet interface unit.

 

All the doors are working by the cards.

 

Could anyone shine any light on this to solve it please.

[FN-GM]

Are all the doors connected to the network directly or is it just 1 connected to the network and then they are daisy chained off each other?

 

When we took on one of our primary schools they had 20 doors daisy chained off each other and 1 connected to the network. The same thing as you described happened. In the end we connected them all directly to the network and the problem was fixed. It was due to them using CAT 5 cable to connect each door together and not the proper cabling that Paxton recommend.

[mickiete]

Thanks for that, but the system has been in for a number of years and working ok ?

[benjie]

Take a look at this document, regards checking the resistance on the data line, linking the control units.

https://www.paxton.co.uk/docs/Application%20notes/AN1061.pdf

[mickiete]

Thanks, will look in to it.

[markberry]

We have around 100 doors connected and we have been getting this issue on some of them. We think it may be down to a cabling issue somewhere on the chain but aren't 100% sure. Some of the daisy chains we have contain a large number of doors. We have been advised to break these down considerably. Over the next break we are getting them either connected directly or into chains of no more than 5 doors.

 

We had one that was a particular problem as it kept going down and it is a main fire exit. We took out the daisy chain connection and connected it to the network. It works perfectly now.

 

I'm not sure why we have such large chains as most of ours have Net2 Plus controllers so are all capable of being connected directly to the network.

[localzuk]

Are all the doors connected to the network directly or is it just 1 connected to the network and then they are daisy chained off each other?

When we took on one of our primary schools they had 20 doors daisy chained off each other and 1 connected to the network. The same thing as you described happened. In the end we connected them all directly to the network and the problem was fixed. It was due to them using CAT 5 cable to connect each door together and not the proper cabling that Paxton recommend.

Erm, Paxton recommend Cat5 or CR8723/C1352A.

 

The way the system works is you have an RS485 line. Each unit is connected in series from what I was told. So, if you have a faulty ACU, you end up losing connectivity between that unit and the end of the line. You could also have a problem with the cabling between the next working ACU and the first one in the line that isn't working. Finally, you may see issues if your line is missing the termination resisters at the 2 ends of the line.

 

We have 14 doors on one line without issue.Paxton recommend using Cat5, or CR8723.

[mickiete]

UPDATE:

Went to site today for another job and decided to have a look at the Net2 system while I was there.

ALL the door are showing online, so looked at the log and for some reason at 1.30am this morning they came back on line.

 

Going to leave it and see if it happens again, I did notice that one ACU was showing more "Not responding" then "Online" than any other.

So if this happens again I think I will go to this unit first.

 

I did notice in the config IP tab that only the Ethernet adaptor was listed and no doors, is this correct for being wired in daisy ?

 

Only asking as our other site uses Net2 Plus units and they are all listed.

[Chris_Cook]

Another thing I've seen cause resets is bad power supplies. It would be worth checking the voltage each ACU is getting - should be about 12v, but not drop down below 11v when active.

[mickiete]

Now you mention reset, I did see in the log one unit say "control unit reset", will check that power supply next time there, as that was not long before all the others came back online.

 

Thanks.

[localzuk]

I did notice in the config IP tab that only the Ethernet adaptor was listed and no doors, is this correct for being wired in daisy ?

Only asking as our other site uses Net2 Plus units and they are all listed.

Yes, the daisy chained ones are using RS485 instead of IP to communicate, so they won't get IPs.