Frustrating Troubleshooting Results
ProgressiveCode
Posts: 64
in AMX Hardware
Had another one of those weird times tonight where hardware troubleshooting results don't really add up. The results are contradictory. I really hate that. We got the problem solved by replacing the master, but it still doesn't make sense.
There are five things wired to the system. Ethernet to a switch connected to Lutron Homeworks and one touch panel. AXlink to several Metreau keypads. RS232 to Aprilaire. RS232 to a NuVo Essentia. Relays to the front gate. Everything is working except NuVo control. So we start troubleshooting.
Checking notifications on the RS232 port showed strings TX to NuVo but nothing RX. Until I changed a setting on the NuVo using its own remote control. Then I got a RX from the NuVo. So the RS232 port obviously was able to receive just fine. I figured maybe the TX on the port got killed somehow. So we changed ports, and used multiple cables. Including the RS232 cable from the working identical system next door. There are only two RS232 ports being used. I tried all ports, and NuVo had the same results. We could RX from NuVo when using its own remote but were not able to control it from the AMX port.
The kicker though was that Aprilaire control worked TX and RX on all ports. And so I started to suspect that maybe the NuVo itself had a bad RS232 port. So I hooked it up to my laptop's terminal... and no, it worked fine. Messages sent and received.
So continuing to scratch our heads we decided to try the NuVo control on another master. And of course it worked right away. So we replaced the master, and now have one that will be sent in for repair. But wtf? Anyway, just felt like sharing.
There are five things wired to the system. Ethernet to a switch connected to Lutron Homeworks and one touch panel. AXlink to several Metreau keypads. RS232 to Aprilaire. RS232 to a NuVo Essentia. Relays to the front gate. Everything is working except NuVo control. So we start troubleshooting.
Checking notifications on the RS232 port showed strings TX to NuVo but nothing RX. Until I changed a setting on the NuVo using its own remote control. Then I got a RX from the NuVo. So the RS232 port obviously was able to receive just fine. I figured maybe the TX on the port got killed somehow. So we changed ports, and used multiple cables. Including the RS232 cable from the working identical system next door. There are only two RS232 ports being used. I tried all ports, and NuVo had the same results. We could RX from NuVo when using its own remote but were not able to control it from the AMX port.
The kicker though was that Aprilaire control worked TX and RX on all ports. And so I started to suspect that maybe the NuVo itself had a bad RS232 port. So I hooked it up to my laptop's terminal... and no, it worked fine. Messages sent and received.
So continuing to scratch our heads we decided to try the NuVo control on another master. And of course it worked right away. So we replaced the master, and now have one that will be sent in for repair. But wtf? Anyway, just felt like sharing.
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Comments
You can repair it yourself if you are careful, the instructions are in another thread.
I get the idea that different devices are more and less sensitive to RS232 signal problems... that has to be it.
That is why Aprilaire was working correctly, but Nuvo was not.
It most likely is the common bad cap problem.
That said, I've had any number of oddball 232 port issues, and the only commonality is the 232 port being in use. Sometimes it will work with one device, and not another ... like John said, some devices seem to be more sensitive. One thing I have noticed a lot is the port RX light going solid, even though there is no activity. When this happens, the entire master usually locks up. Because of that, I have a hunch it's in the second order chipset ... not the ones directly controlling the port, but the ones interfacing the port chips to the rest of the controller ... but that's a hunch, not a definite. It seems unrelated to the capacitor issue (ie., a separate issue). I have seen it on X000 series controllers, and X100 series controllers.
I can't remember for sure, but I think there is a difference in the wiring for a 422 rig. I seem to remember something about either the A and B plus sides being strapped together as well as the A and B minus. Or that they all go separately to pins 1,6 and 5,9 (the four corners of the D-sub 9 connector) or some such thing. He may want to double check the wiring diagram just to be on the safe side.
Either way, the8thst is correct that you should double check.
You are correct. I was thinking 485, but mistakenly typed 422. The aprilaire tstats operate on a 485 bus with an optional 485 -> 232 converter.
I always controlled the tstats straight through 422 and did not sure the converter, so that is what would work even if the 12v 232 capacitor failed.
The variation on the appearance of this issue is incredible. You are running 100%, but I have fairly direct knowledge of well over 200 netlinx installs in operation, exactly one (my very own ancient 3000) has verifiably failed ala capacitors. Two others went back to AMX for serial problems before the cap problem was this well defined, but at least one of those was a lightning strike issue... so worst case, our experience is 1.5%, probably less. What could explain the difference in incidence?
We have also had to send in about 80% of our NI-X000 processors for the bad cap problem.
You must be really lucky.
That 200 or so install base is spread across about 30 dealers I personally work with closely enough to have known if they had this issue (they would need a new software license from me for the new NetLinx serial number, pretty conclusive). We discuss this issue at training because of the evidence that it will increase as the units age, and very few say they encountered something like this ever... so far.
It would be good to hear more failure rate estimates from more of the forum members... high or low.
Have they repaired any 2000 or 3000 units free? They've been out of production for 6 years or more... what was the decider on why they didn't do 2 of them?
As to the problem with 232, I know this gets brought out every time one of these things comes up, but anything on the AMX port that uses other than pins 2, 3, and 5 can hose up communications. AMX puts signals on 1, 4, and 6 for the RS422 and some equipment may not respond well to these signals. Also, some "null modems" do funny things with pins 1, 4, and 6 and can hose communications. For example, the little adapters that come with the Polycom codecs, if connected to the AMX, will screw things up. If connected to the Polycom (and the AMX is connected with 2, 3, and 5) it works ok. Just something to consider when odd RS232 problems appear.
1 of > 100 NI-x000 units in the field (though AMX replaced the cap in another unit that was in for repair for another reason).
Personally, I've seen more of the solid-lit-RX-light-and-lockup issue than loss of communications in general. Of course, when it locks up, you can presume loss of communications too.
You mentioned another thread where there were instructions about how to replace the capacitor yourself. I have not been able to find this thread so far. If anyone knows where it is, please reply.
Regarding my reported symptoms, I have been informed by the installer that he thinks the Aprilaire is wired RS422 and not RS232 as I had thought. So that does fit with the capacitor problem. It will be cheaper for us to try to repair the capacitor ourselves than to ship it overseas back to AMX for repair.
Here you go:
http://www.amxforums.com/showthread.php?7064-Problem-Controlling-Sierra-Pro-Switcher&p=48733#post48733
Could also be environmental. We try to ensure that gear is installed in a suitably ventilated if not climate controlled location; I see a hell of a lot of (other people's) installs where the gear is hot enough to fry eggs on though.
Just a data point... in all the installs I do know about, I don't think there is even ONE with -no- RS232.
And I don't think I've -ever- seen and only heard about ONE with a locked up incoming light. Well, not counting bad wiring of connectors!
And we preach VENTILATION. Not that everyone gets the religion.
I have not seen the locked up incoming light problem either.
All of the NI that lost 232 support were in proper equipment racks with proper cooling except for 1 (which was in a fairly warm cabinet), so I don't think temp is the commonality in failures.
We do use RJ45->RS232 adapters. Maybe they add just enough capacitance and/or resistance to stress the PS cap? Do all of your dealers solder on proper stranded wire to DB9 connectors?