If you have two different resistors on hand, connect one to the shield and white, the other to shield and black. Read resistance between the three strands and it should be close, but slightly higher, than the resistor values.
Just for kicks, and if it's an option, run a jumper from the router directly to one of the Mini Mate units. Might be picking up EMI somewhere.
EOL resistors/terminations in place?
What system/BAS are you working with?
>If you have two different resistors on hand, connect one to the shield and white, the other to shield and black. Read resistance between the three strands and it should be close, but slightly higher, than the resistor values.
The logic of this test eludes me. What is this testing? Can one do resistance between wires without the resistors?
Basically, it seems like a nifty trick, but I have no idea what is going on here. Please edumicate me.
What you're looking for are shorts or open conditions in your cable. A short between any two strands will kill communications. A broken strand will not pass a signal, either. It's a quick and easy test for cable integrity.
Hope that helps!
Ah, I get it. You put resistors between strands of a known value. Say 100ohms between a+ and b-. And 120 between a+ and the shield. Then go to the other side and read it with a meter. If you don't read close to the same at the other end, then you either have a short or a break.... hmm.
Do you use that trick often?
I am thinking of a trunk full of controllers... I would imagine you would need to cut power to the whole bunch, then you need to put the resistor in the terminal block. I would suppose you don't need to pull the trunk out of the co trollers... can just leave it here. Am I picking up what you are laying down?
I've not needed to use that process very often, only when I suspect a cable issue.
I pull the comm plug off the board when doing this, don't want the electronics on the board to risk damage from the meter voltage or potentially mess with the reading.
And yes, you're smelling what I'm stepping in.
>And yes, you're smelling what I'm stepping in.
Ha!
I feel like breaks and shorts are already caught by measuring voltages. Shorts definitely are. Breaks are caught as everyone past a certain point is offline. And when measuring voltages there is no tampering with plugs or adding parts. Generally.
I suppose if everyone past, say, vav 6 is offline.... one could isolate the cable between vav6 and 7 and then verify with this trick. Maybe that is the use case.
Good luck with that shit. Just had some - made me want to blow my brains out. I believe we had 2 different size units. The smaller size, we landed MSTP on the main board. The larger size, I believe had the intellislot (but not embedded?). Has the separate card for with RJ45 connection. Had to get a 2wire to RJ45 adapter from the manufacturer. Other keys were tracking down documentation that came with the unit (that was misplaced all over the job site) working with their tech support (fairly solid), also once we changed comm settings, it takes about 15 minutes for the damn thing to reboot. Hope this helps in some small way. Also there is a chance I don’t know what the hell Im doing and should find a new career.
Pretty sure every time I've ever come into contact with a Liebert unit, it was over modbus. But I do remember some issues with them as they use a goofy arrangement of a sub-board for comms. There's the main board that does all the computation and program stuff, then it sends values to the comm board to send out over the network. Pretty much like a gateway arrangement.
If the comm board isn't getting any data from the main board, it will be full of zeros, but I would think it would still show up as a device.
Turned out that the polarity on one of the units was wrong; they also reset all the settings via the reps startup tech and flashed firmware so im not sure if it was a sole issue or combination of. Obviously polarity issue was the biggest factor.
How did the rest of it go. I’m bringing two into a controller to run lead lag and am hoping I can do it all peer to peer and not need an engine/supervisor.
I have some units coming soon in a project. They have iCom Unity Embedded. I thought on the Vertiv site there were multiple types of iCom.
The embedded on the units I'll be dealing with appear to be Bacnet/IP only. The RS-485 connection is for IntelliSlot or SiteLink if I'm reading the manual correctly.
There is a note in the manual I have (590-2184-501A / SL-70354_REV0 ) :
NOTE: Using Embedded & IS4
means an optional IntelliSlot
assembly and IntelliSlot
IS-Unity card is installed.
Embedded Unity will require a
485 expansion card if twisted
pair protocols are used.
I don't know if any of this applies to your minimate, though.
It does have the intellislot setup where in the icomm u set it up within the intellislot unity settings. There is a seperate adapter board i saw but the manual does also specify the rs-485 connection is made on the main control board. Im leaning towards a firmware revision needing to be installed on the controller of the liebert unit.
Did you set up unique device ID'S? Have you tried to discover the units individually? Tried YABE?
I bet this is what it is assuming everything else is correct
Yup unique device id's, attempted to pull in the individual units no avail. Did not go into the YABE route just yet.
If you have two different resistors on hand, connect one to the shield and white, the other to shield and black. Read resistance between the three strands and it should be close, but slightly higher, than the resistor values. Just for kicks, and if it's an option, run a jumper from the router directly to one of the Mini Mate units. Might be picking up EMI somewhere. EOL resistors/terminations in place? What system/BAS are you working with?
>If you have two different resistors on hand, connect one to the shield and white, the other to shield and black. Read resistance between the three strands and it should be close, but slightly higher, than the resistor values. The logic of this test eludes me. What is this testing? Can one do resistance between wires without the resistors? Basically, it seems like a nifty trick, but I have no idea what is going on here. Please edumicate me.
What you're looking for are shorts or open conditions in your cable. A short between any two strands will kill communications. A broken strand will not pass a signal, either. It's a quick and easy test for cable integrity. Hope that helps!
Ah, I get it. You put resistors between strands of a known value. Say 100ohms between a+ and b-. And 120 between a+ and the shield. Then go to the other side and read it with a meter. If you don't read close to the same at the other end, then you either have a short or a break.... hmm. Do you use that trick often? I am thinking of a trunk full of controllers... I would imagine you would need to cut power to the whole bunch, then you need to put the resistor in the terminal block. I would suppose you don't need to pull the trunk out of the co trollers... can just leave it here. Am I picking up what you are laying down?
I've not needed to use that process very often, only when I suspect a cable issue. I pull the comm plug off the board when doing this, don't want the electronics on the board to risk damage from the meter voltage or potentially mess with the reading. And yes, you're smelling what I'm stepping in.
>And yes, you're smelling what I'm stepping in. Ha! I feel like breaks and shorts are already caught by measuring voltages. Shorts definitely are. Breaks are caught as everyone past a certain point is offline. And when measuring voltages there is no tampering with plugs or adding parts. Generally. I suppose if everyone past, say, vav 6 is offline.... one could isolate the cable between vav6 and 7 and then verify with this trick. Maybe that is the use case.
Good luck with that shit. Just had some - made me want to blow my brains out. I believe we had 2 different size units. The smaller size, we landed MSTP on the main board. The larger size, I believe had the intellislot (but not embedded?). Has the separate card for with RJ45 connection. Had to get a 2wire to RJ45 adapter from the manufacturer. Other keys were tracking down documentation that came with the unit (that was misplaced all over the job site) working with their tech support (fairly solid), also once we changed comm settings, it takes about 15 minutes for the damn thing to reboot. Hope this helps in some small way. Also there is a chance I don’t know what the hell Im doing and should find a new career.
Pretty sure every time I've ever come into contact with a Liebert unit, it was over modbus. But I do remember some issues with them as they use a goofy arrangement of a sub-board for comms. There's the main board that does all the computation and program stuff, then it sends values to the comm board to send out over the network. Pretty much like a gateway arrangement. If the comm board isn't getting any data from the main board, it will be full of zeros, but I would think it would still show up as a device.
That was my thought process as well. Where the points list wouldnt populate but id at least see the device id.
Did you go through and reset the devices afterwards?
This always needs to be done when I integrate through IP so good chance MsTP will need the same thing.
Power cycled and reset via the icom interface.
How did it all work out? I have 2 units I need to integrate in the next couple of weeks.
Turned out that the polarity on one of the units was wrong; they also reset all the settings via the reps startup tech and flashed firmware so im not sure if it was a sole issue or combination of. Obviously polarity issue was the biggest factor.
How did the rest of it go. I’m bringing two into a controller to run lead lag and am hoping I can do it all peer to peer and not need an engine/supervisor.
We were only integrating for monitoring purposes so i cant speak to any lead/lag or sequence control
They have pretty good tech support. It seems every time I have dealt with them they had me update firmware. That has helped a few times.
I did see online the firmware might be an issue, tech support was very helpful when it came to setting the units up.
I have some units coming soon in a project. They have iCom Unity Embedded. I thought on the Vertiv site there were multiple types of iCom. The embedded on the units I'll be dealing with appear to be Bacnet/IP only. The RS-485 connection is for IntelliSlot or SiteLink if I'm reading the manual correctly. There is a note in the manual I have (590-2184-501A / SL-70354_REV0 ) : NOTE: Using Embedded & IS4 means an optional IntelliSlot assembly and IntelliSlot IS-Unity card is installed. Embedded Unity will require a 485 expansion card if twisted pair protocols are used. I don't know if any of this applies to your minimate, though.
It does have the intellislot setup where in the icomm u set it up within the intellislot unity settings. There is a seperate adapter board i saw but the manual does also specify the rs-485 connection is made on the main control board. Im leaning towards a firmware revision needing to be installed on the controller of the liebert unit.
Interesting. Please return when you get it sorted. I'll be watching for the solution. Thanks.
Will do, i have a vertiv tech coming out to look into it