RoTaTech
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TI-565 problem with RBC and RCC– long read...
An old Harris press, that has been out of service for a couple years, is being resurrected.
I am commissioning a TI565 system with one RCC, 16 Remote Bases, on the RG-6 coax. There is a Magnavox 5900A (20) tap at every RBC except the last (unit 4). There is also a grounding joint between every tap and the RBC.
The bases are Channel 1 Rack 0,2,3,4,5,6,7,8,9,10,11,12,13, and Channel 2 Rack 0,1,2.
IO slots in Bases 6 through 13 are configured identically (addresses are different, of course)
Symptoms:
It was powered up several weeks ago, with no apparent problem. I just arrived on Tuesday. Rack 13, and less frequently, Rack 12 were randomly blinking outputs. This was not noticed, (but may have been happening) before I arrived. Evidently it was blink outputs every few minutes, or approximately once/minute.On Wed., we get the outputs blinking several times per second, then random pause(10-60sec), then another burst of blinks.
Channel 2 seems fine.
Monitoring STW1, I see rack 12 and 13 changing from 0 to 1 – sometimes both, sometimes only 13. I have not seen 12 blink alone.
If I monitor STW145, we get a 'clump' of timeout errors exactly when the outputs blink. As well, if I look at some of the inputs from rack 13/12, they are flickering in the ladder.
So, obviously a problem with rack 13, right?
We took the RBC from rack 13, changed ID to 10, and put it into rack 10; took RBC from rack 10, changed it to ID13, put it in rack 13. Problem remains with ID13/rack 13.
Maybe flaky power?
We exchanged power supplies from 10-13. Problem stays at 13.
We exchanged every IO card from 10-13. Problem stays at 13.
So it must be bad cabling?
We unscrewed and reconnected every joint on the network, RCC, RBC, ground joints, and daisy chain taps. Some bad joints were found before I arrived, and they had been replaced – joint and suspect cable.
We did find one improperly stripped center conductor on a new connection, not on ID13.
The coax seems correctly terminated and has no opens or shorts at DC (i.e. With a multimeter) If I put a terminator on the coax at each unit, I can read the 75 ohms. By the far end of the line, we get 107ohms.
Physically, the network is wired RCC-0-2-3-13-12-11-10-9-8-7-6-5-4, so the problem is not at the end of the cabling.
So it must be the rack/backplane at 13?
We pulled a spare 16 slot rack from another machine, and put ONLY RBC13 and power supply 1, and parked it on the floor
.
Same errors in STW1 and STW145.
OK, then it's a bad ground or bad splitter at rack 13?
We put a new, newly terminated cable DIRECTLY from RCC channel 1 to RBC 13 – no old cable, no splitter, no noise or ground issues. Same errors in STW1 and STW145.
(*I have heard two conflicting opinions on this: one says that without the attenuator, it overloads the RBC and cannot properly communicate; the other says that he has seen TI networks with no splitters.*)
Now, here is the oddest part: changing no hardware, just exchanging the ID rotary switch from 10 to 13 and 13 to 10, *the problem stays with Base 13!! *
OK, the PLC and/or RCC has a misconfigured or corrupt base 13.
I checked the IO config for 11,12,13. There are no overlapping addresses. Besides, this thing had worked for 20+ years with that configuration.
I did a complete upload of the PLC, saved it, CleaRed the PLC, reloaded from a CD backup (from 2002). Same errors in STW1 and STW145.
I CLRBS clear base 13, rebuilt the configuration, and reloaded. Same errors in STW1 and STW145.
Three points of interest:
When I put the PLC into Program mode, all the output modules retain their status. If I power down and power up (in program or run) all the output modules retain their status. This is a dangerous safety issue!
The AC power supply at rack 13 draws approx. 0.3-0.4 Amp AC and is very warm; the other modules (identical IO configuration) draw about 0.2A.
On a Win98 computer, I copied the program directory onto its hard drive. When I try to go online I get a Disk Write Error. I did check the attribute bits on both the Directory and each file; they are not ReadOnly.
Anyone have an idea? Four days so far, and I'm out of ideas...
An old Harris press, that has been out of service for a couple years, is being resurrected.
I am commissioning a TI565 system with one RCC, 16 Remote Bases, on the RG-6 coax. There is a Magnavox 5900A (20) tap at every RBC except the last (unit 4). There is also a grounding joint between every tap and the RBC.
The bases are Channel 1 Rack 0,2,3,4,5,6,7,8,9,10,11,12,13, and Channel 2 Rack 0,1,2.
IO slots in Bases 6 through 13 are configured identically (addresses are different, of course)
Symptoms:
It was powered up several weeks ago, with no apparent problem. I just arrived on Tuesday. Rack 13, and less frequently, Rack 12 were randomly blinking outputs. This was not noticed, (but may have been happening) before I arrived. Evidently it was blink outputs every few minutes, or approximately once/minute.On Wed., we get the outputs blinking several times per second, then random pause(10-60sec), then another burst of blinks.
Channel 2 seems fine.
Monitoring STW1, I see rack 12 and 13 changing from 0 to 1 – sometimes both, sometimes only 13. I have not seen 12 blink alone.
If I monitor STW145, we get a 'clump' of timeout errors exactly when the outputs blink. As well, if I look at some of the inputs from rack 13/12, they are flickering in the ladder.
So, obviously a problem with rack 13, right?
We took the RBC from rack 13, changed ID to 10, and put it into rack 10; took RBC from rack 10, changed it to ID13, put it in rack 13. Problem remains with ID13/rack 13.
Maybe flaky power?
We exchanged power supplies from 10-13. Problem stays at 13.
We exchanged every IO card from 10-13. Problem stays at 13.
So it must be bad cabling?
We unscrewed and reconnected every joint on the network, RCC, RBC, ground joints, and daisy chain taps. Some bad joints were found before I arrived, and they had been replaced – joint and suspect cable.
We did find one improperly stripped center conductor on a new connection, not on ID13.
The coax seems correctly terminated and has no opens or shorts at DC (i.e. With a multimeter) If I put a terminator on the coax at each unit, I can read the 75 ohms. By the far end of the line, we get 107ohms.
Physically, the network is wired RCC-0-2-3-13-12-11-10-9-8-7-6-5-4, so the problem is not at the end of the cabling.
So it must be the rack/backplane at 13?
We pulled a spare 16 slot rack from another machine, and put ONLY RBC13 and power supply 1, and parked it on the floor
.
Same errors in STW1 and STW145.
OK, then it's a bad ground or bad splitter at rack 13?
We put a new, newly terminated cable DIRECTLY from RCC channel 1 to RBC 13 – no old cable, no splitter, no noise or ground issues. Same errors in STW1 and STW145.
(*I have heard two conflicting opinions on this: one says that without the attenuator, it overloads the RBC and cannot properly communicate; the other says that he has seen TI networks with no splitters.*)
Now, here is the oddest part: changing no hardware, just exchanging the ID rotary switch from 10 to 13 and 13 to 10, *the problem stays with Base 13!! *
OK, the PLC and/or RCC has a misconfigured or corrupt base 13.
I checked the IO config for 11,12,13. There are no overlapping addresses. Besides, this thing had worked for 20+ years with that configuration.
I did a complete upload of the PLC, saved it, CleaRed the PLC, reloaded from a CD backup (from 2002). Same errors in STW1 and STW145.
I CLRBS clear base 13, rebuilt the configuration, and reloaded. Same errors in STW1 and STW145.
Three points of interest:
When I put the PLC into Program mode, all the output modules retain their status. If I power down and power up (in program or run) all the output modules retain their status. This is a dangerous safety issue!
The AC power supply at rack 13 draws approx. 0.3-0.4 Amp AC and is very warm; the other modules (identical IO configuration) draw about 0.2A.
On a Win98 computer, I copied the program directory onto its hard drive. When I try to go online I get a Disk Write Error. I did check the attribute bits on both the Directory and each file; they are not ReadOnly.
Anyone have an idea? Four days so far, and I'm out of ideas...
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