Interlogix NX-320E

[lanbrown]

So I'm thinking of adding an NX-320E to my NX-8E system.  Currently the cabinet is a bit full and since I was going to add multiple rate of rise sensors heat sensors in the attic, I was thinking of putting a cabinet in the attic for the NX-320E along with another NX-216E zone expander to handle them.  It will make the wire runs shorter for the rate of rise sensors and I won't have to get them down the wall either.
 
Currently I have the NX-8E, one NX-216E, one NX-595E, one NX-584E, one LED keypad and one LCD keypad.  I don't know how close I am to the power capacity.  I might add a third a keypad, another LCD.  Currently there is just a single battery in the cabinet.  So I could move the current LCD keypad to the NX-320E since those keypads take more power.
 
Here is my question, I looked at the instructions and I see the input from the NX-8E, data goes to data and common goes to common and then the positive on the NX-320E goes to the Aux+ on the NX-8E.  Since the NX-320E is also a bus extender, I don't see where you connect the POS to since the output terminal wise has a common and a data but no POS.  Do you use one of the Out (either A, B or C) to power say the NX-216E or keypads?  I see in the instructions for location 0 on segment 1, that you can set it to always on.  The instructions don't say if this is how you handle using it as a bus extender but they do list the NX-216E as compatible.  So that is the only thing I can see how to wire it up.
 
Here are the NX-320E instructions:
https://objects.eanixter.com/PD348302.PDF

 

[RAL]

I'm not an expert on the NX8E, but here's my take on how the 320E should be connected.
 
On the expansion boards, such as the 216E, the POS terminal is used to supply power to the expansion unit, since it has no internal power supply.
 
The 320E is different, since it is a power supply.  With almost all other systems, you never want to connect the outputs of different power supplies together, as they end up fighting each other.  So it puzzles me a bit that the 320E contains a POS input terminal.  Unless perhaps it is just a dummy and not really connected to anything.
 
I would connect the Data and Com terminals back to the NX-8E and leave POS unconnected and see if that works.
 
For the outputs, these can be used as relay controlled, switched power outputs, or as always-on power outputs.  So you could set output A to be always on, and use it to power a keypad.
 
An interesting test would be to see whether the POS terminal has 12V one it when the 320E is powered up (and POS is not connected back to the NX-8E).  If so, then you might be able to use this as a power output to the keypad.

I would not put the 320E in the attic. The specs say that the operating temperature is 32 to 120 degrees F. The high temperatures may cause operational problems and may lead to premature failure.

 

[lanbrown]

Ral,
 
Thanks.
 
It would have been nice if the directions actually showed how the NX-320E is used as a bus extender.  I believe that since it can be used as a bus extender, this is why is has power and data inputs.  RS485 doesn't handle voltage differential well at all; so the NX-320E would need to isolate one RS-485 communication bus from the other.  So this is why on the input of the NX-320E is has POS, Com and Data.  So it is puzzling that there is no POS on the output.  If connected to the POS from the NX-8E panel, then you're using that power supply.  It is not like they make it easy to figure out how much power you're actually using since VA deals with loss/resistance by using a power factor that is between 0 and 1.
 
I've already thought about the temp aspect; the hottest the attic ever got was 114 degrees and that was on a day with a temp of 108 outside.  So the attic stays relatively cool.  I was also planning on keeping the panel lower in the attic as well.  If it fails, I will just need to rethink it.

 

[RAL]

I don't think the NX data bus is RS485.  RS485 is differential, and has Data-A and Data-B signals, both independent of ground/common.  The NX appears to be a single ended bus of some type, but I'm not sure what it is.
 
I agree that it is strange that they don't put a POS terminal on the output side for keypads and such to connect to.  I guess they figure that you would just dedicate one of the controlled outputs as an always-on output and use that.  But why should you give up a programmable output for that purpose?  They sure could write better instructions on what the connections should be.

 

[lanbrown]

Once I get the NX-320E I'll see how it all works using one of the outputs to power an expansion module or two.  At least our thinking is the same, it must be an output that is used.  Maybe they did it because you're limited power wise on the extender so maybe it is easier to figure out power requirements/limitations?
 
 
I have a spare NX-584E and there is only around 3 chips on it or so.  I should see if I can read the part numbers on the chips as that might tell what the bus is.  One of the chips has to be the interface to the bus.  My thinking that it is RS-485 is because I highly doubt Caddx had the resources to make their own custom chips.  That would get expensive and slow development down.  So I'm thinking it was something off the shelf.
 
Also, I almost view the UltraSync system as an extension of the NX family, just updated and packaged differently.  The NX line and the UltraSync line both utilize DLX900.  So the heart of the system seems to be similar.  Interlogix also states that the UltraSync has an encrypted RS-485 bus and looking at the diagram, it uses three wires.  They reference them in a different way though.  Look at page 22:
https://static.interlogix.com/library/ultrasync-modular-hub-reference-manual.pdf
 
They call them LAN +, LAN - and NEG.  RS485 only needs three wires; five if you want duplex.  The third or fifth wire is a GND.  So for the UltraSync that appears to be the NEG.  The LAN + and LAN - would be the data pairs.  On the NX series they list Data, COM and POS.  So the POS could equivalent to the LAN +, the Data could be LAN - and the COM the NEG.
 
The NX series says 2500 feet distance, the UltraSync says 2600 feet.  The extra 100 feet could be better RS-485 bus interface chips.
 
I wish I had the protocol analyzer from an old job.  It had various connectors and you use the corresponding connector for the interface you need to look at.  It supported RS232, RS422 and RS485 among others.  It was an old HP box; probably Agilent these days.
 
I have a spare NX-8E panel and keypad.  Maybe I should look at one of these to see if it is RS-485:
http://www.fte.com/products/serialanalyzers.aspx
 
If it is RS-485, it does make some things easier.  There are converters so you can just put that traffic on fiber; they even allow for point-to-point, star configurations and daisy chaining.  On the headend for a star, you just have multiple and they all get the same data and then send it to the remote nodes.  The speed is limited to a max of 500kbps though.  Caddx could have used RS485 but what the encoding used could still be a mystery.

 

[RAL]

Once I get the NX-320E I'll see how it all works using one of the outputs to power an expansion module or two.  At least our thinking is the same, it must be an output that is used.  Maybe they did it because you're limited power wise on the extender so maybe it is easier to figure out power requirements/limitations?
 
 
I have a spare NX-584E and there is only around 3 chips on it or so.  I should see if I can read the part numbers on the chips as that might tell what the bus is.  One of the chips has to be the interface to the bus.  My thinking that it is RS-485 is because I highly doubt Caddx had the resources to make their own custom chips.  That would get expensive and slow development down.  So I'm thinking it was something off the shelf.
 
Also, I almost view the UltraSync system as an extension of the NX family, just updated and packaged differently.  The NX line and the UltraSync line both utilize DLX900.  So the heart of the system seems to be similar.  Interlogix also states that the UltraSync has an encrypted RS-485 bus and looking at the diagram, it uses three wires.  They reference them in a different way though.  Look at page 22:
https://static.interlogix.com/library/ultrasync-modular-hub-reference-manual.pdf
 
They call them LAN +, LAN - and NEG.  RS485 only needs three wires; five if you want duplex.  The third or fifth wire is a GND.  So for the UltraSync that appears to be the NEG.  The LAN + and LAN - would be the data pairs.  On the NX series they list Data, COM and POS.  So the POS could equivalent to the LAN +, the Data could be LAN - and the COM the NEG.
 
The NX series says 2500 feet distance, the UltraSync says 2600 feet.  The extra 100 feet could be better RS-485 bus interface chips.
 
I wish I had the protocol analyzer from an old job.  It had various connectors and you use the corresponding connector for the interface you need to look at.  It supported RS232, RS422 and RS485 among others.  It was an old HP box; probably Agilent these days.
 
I have a spare NX-8E panel and keypad.  Maybe I should look at one of these to see if it is RS-485:
http://www.fte.com/products/serialanalyzers.aspx
 
If it is RS-485, it does make some things easier.  There are converters so you can just put that traffic on fiber; they even allow for point-to-point, star configurations and daisy chaining.  On the headend for a star, you just have multiple and they all get the same data and then send it to the remote nodes.  The speed is limited to a max of 500kbps though.  Caddx could have used RS485 but what the encoding used could still be a mystery.

 
I agree that they probably would have used something off-the-shelf rather than designing their own interface. 

I don't think they are using the POS terminal as the other data signal, since POS and COM are used to provide power to the keypads and other data bus devices. 
 
RS423 is a single-ended version of RS-422. Perhaps that's what the NX uses.
 
A serial analyzer would be very handy.  The interface hardware is cheap, but the software is usually expensive. 

 

[lanbrown]

That HP was an all in one.  It was a luggable PC though.  Best use I ever used it for was when security was swapping out the badge system many years ago.  They had an issue and I used it (HP) while sitting in the middle and watching the communication.  I suggested to security that they should be using encryption for the communication and they were adamant that it was there.  So I had them use their badge while that was plugged in and proceeded to use their "badge" on other doors by just replaying the original request with the only change being the reader ID.  These days that would be even easier since you don't need a luggable computer anymore.
 
The UltaSync uses three pairs and provides power to the keypads as well.  Interlogix says RS-485 on the documentation.  What they call them and what they do can be two different things.  You do need to connect them up properly, so Pos to Pos, Com to Com and Data to Data.  Maybe Pos is 12VDC, the Com is actually shared with being the negative side while also being the Data -.  The Data is then Data +.  
 
I excluded RS-422 before because well, the standard calls for 6v.  RS-423 looks to be the same.  I guess Caddx could have used it and modified it accordingly, but getting chips designed for 6v to work at 12v seems a bit tricky.  Then again, look at RS-232, it can be one of many voltages but almost everything these days seem to only support 5V.

 

[JimS]

Was it ever determined what standard the communication was?  I am running cables between buildings and wanting to do some sort of isolation/surge protection.