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Network terminator needed?


DrWizard
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Not only have I added a lot to my show this year, but the old stuff has gotten moved around to integrate the new stuff.  With so many changes it's hard troubleshoot stuff that worked last year...

I added 2 new controllers this year, but they are not talking.  The network (RS-485) cables are somewhat long and I'm thinking I may need a network terminator at the end of the line.  But I didn't need one last year with 3 controllers 200' from end to end.

  • Computer connects with a red HS enhanced adapter with a 5' cable to a CTB24Dg3 (#1).
  • CTB24D connects with a 75' cable "A" to new CTB16PCg3 (#2)
  • From there with a 100' cable "B" to a LOR1602wg3.(#3)
  • From there with a 10' cable to #4, and from there with a 50' cable to #5, but I haven't gotten that far yet...
  • With just the first 2 controllers connected, the Hardware Utility sees both of them.
  • When I connect the 3rd controller, the HU only sees the very first one.
  • If I bypass the 2nd controller, and connect the first to the third, the HU sees both controllers.
  • If I change the order to 1-3-2 the HU only sees the first controller.
  • The cables have been tested with a fancy-shmancy TDM tester that checks for capacitance, crosstalk and all sorts of other conditions and they all test just fine.

So do I need to add a 120 ohm resistor across pins 4 and 5 on the last controller on the line?

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I would double check the jacks on controller #2.  You might have some bent pins/bad jacks.  I would also try a different cat 5 cable.  Just because it tests fine doesn't mean it will work (something I've learned the hard way myself).

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As far as a termination, the RS-485 requires a 120 ohm termination at both ends of the network, up to 32 nodes on the network. and a total length of 4,000 feet.   Most of us are running far less than 32 modes far less than 4,000  feet total length, so most of the time we can get away without a termination.  Personally, I installed terminations on my three LOR networks.  There was a thread several years ago on another forum here someone posted O'Scope photos of his network with and without terminations.  The difference was impressive.

I'm with jfuller on this one, carefully check the jacks for damaged or mis-aligned pins.

 

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On 11/23/2018 at 6:34 PM, DrWizard said:

Not only have I added a lot to my show this year, but the old stuff has gotten moved around to integrate the new stuff.  With so many changes it's hard troubleshoot stuff that worked last year...

I added 2 new controllers this year, but they are not talking.  The network (RS-485) cables are somewhat long and I'm thinking I may need a network terminator at the end of the line.  But I didn't need one last year with 3 controllers 200' from end to end.

  • Computer connects with a red HS enhanced adapter with a 5' cable to a CTB24Dg3 (#1).
  • CTB24D connects with a 75' cable "A" to new CTB16PCg3 (#2)
  • From there with a 100' cable "B" to a LOR1602wg3.(#3)
  • From there with a 10' cable to #4, and from there with a 50' cable to #5, but I haven't gotten that far yet...
  • With just the first 2 controllers connected, the Hardware Utility sees both of them.
  • When I connect the 3rd controller, the HU only sees the very first one.
  • If I bypass the 2nd controller, and connect the first to the third, the HU sees both controllers.
  • If I change the order to 1-3-2 the HU only sees the first controller.
  • The cables have been tested with a fancy-shmancy TDM tester that checks for capacitance, crosstalk and all sorts of other conditions and they all test just fine.

So do I need to add a 120 ohm resistor across pins 4 and 5 on the last controller on the line?

Double check each of your unit IDs.  I found out the hard way when purchasing new items this year it had instructions to change unit IDs via the HU.  As it turns out those instructions are

outdated.

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Out of the frying pan, into the fire...

I noticed right away (Before I ever posted) as I unpacked everything from last year that the contacts on the cables were corroded.  I cut all of them off and put new ones on, and tested them all with a very expensive Time-Delay-Multiplexer cable tester.  It checks ALL the electrical characteristics of the cable.  There is no such thing as a perfect cable, and this tester tells you if everything is within specifications for cat5, cat5e, cat6, cat7...  And I swapped cables around and tried several different ones anyway despite testing good.  Turns out the cheap cable connectors also caused the RJ-45 jack pins in 2 of the controllers to corrode as well.  Got those all cleaned up.

Hardware Utility now sees all 5 controllers on the AuxA network, shows the Unit IDs (all unique),, model number, firmware revision, etc.

Can control the lights on the first 2 controllers, but not on the last 3.  Cant control 'em from HU or from Sequence Editor.  Have double, triple, quadruple checked all settings for unit IDs, circuit/channel #s, and Network in the sequences, and the Network config.  Everything seems to be exactly as I think it should be, and I'm stumped as to why it's not working.  I'm not new at this, been using LOR since 2006 and I'm an electrical engineer.  I have however, been known not to see the forest because of all the trees...

Tomorrow I'm gonna try things such as using my spare RS-485 adapter, changing to non-enhanced mode, and chaining the other 5 controllers after the old Gen 1 one on the primary network.

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One controller is an old LOR1602W "Model 3" (blue board).  It is the only controller on the primary network using an old black RS-485 adapter.

The AuxA network is set for enhanced mode and uses a red high-speed RS-485 adapter and has 5 controllers consisting of:

  • 1 CTB24D, Gen 3, 2½  yrs old.
  • 2 LOR1602Wg3's Gen 3, 2½ yrs old.
  • 2 CTB16PCg3's, Gen 3, 7 mo.s old, bought at this year's spring sale.

Network goes from 'puter thru 5' cable to the CTB24 (LOR ID 6),

  • then thru a 40' cable to a CTB16 (ID 4),
  • then thru a 75' cable to a 1602 (ID 3),
  • then thru a 10' cable to the other 1602 (ID 2),
  • then thru a 30' cable to the other CTB16 (ID 5), which has a 122.6Ω terminator.

HU as mentioned, sees all 5 controllers correctly, but will only control lights on the first two: the CTB24 and the CTB16.  Screenshot attached.

Green LEDs on the CTB16's are solid green (indicating receiving a heartbeat) and displays on the new 1602's show the LOR ID (and do NOT display "no conn")

Software is 4.3.36 Pro.  (Will switch to 5.x after the holiday)

LOR_HU_Screenshot.jpg

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In between bouts of rain I did some more extensive troubleshooting today.

Turns out my LOR1602Wg3's are not working with enhanced mode.  Hmmm-- Why?

Moving this to a new thread...

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