Thursday, March 31, 2021, 14:42
EVAP1's TGHT has been tripping even when the pressure is below the tripping limits. The temperature of the turbo pump and the TGHT's power supply were monitored discarding the possibility of tripping due to the overheating of these pieces of equipment.
Gelo has been monitoring the IGP1 during carbothermal reductions to pinpoint the tripping issue, below is Gelo description to the issue and the patch he implemented to fix it.
"IGP loses its STATON (On status) if the value from the device is not within the valid voltage window (0.7 to 10 V). IEVAP:IGP1 for some reason goes to 0V for a few seconds then goes back up to where it left off.
Prior to the latest software updated, I added a 2 second delay in the code so that any invalid signal <=2s will be ignored.
Here is the data that you sent me specifically looking at when it tripped. I also attached the data that you sent me. << File: 310321-P2N-3-CR (1).txt >>
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Time
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IEVAP:TGHT:RDVOL [V]
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IEVAP:TGHT:RDCUR [A]
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IEVAP:IGP1:RDVAC [T]
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|
03/31/2021 12:00:25
|
3.07
|
740.9
|
0.01866428
|
|
03/31/2021 12:00:26
|
3.07
|
741.1
|
0.01838651
|
|
03/31/2021 12:00:27
|
3.07
|
740.7
|
0.01838651
|
|
03/31/2021 12:00:28
|
3.07
|
740.8
|
0.01797758
|
|
03/31/2021 12:00:29
|
3.08
|
740.9
|
0.0178433
|
|
03/31/2021 12:00:30
|
3.08
|
740.6
|
0.0178433
|
|
03/31/2021 12:00:31
|
3.08
|
740.8
|
0
|
|
03/31/2021 12:00:32
|
3.08
|
741.1
|
0
|
|
03/31/2021 12:00:33
|
0.14
|
42.2
|
0.01680456
|
|
03/31/2021 12:00:34
|
0
|
3.3
|
0.01513015
|
|
03/31/2021 12:00:35
|
0
|
3.4
|
0.01071685
|
|
03/31/2021 12:00:36
|
0
|
3.2
|
0.00788081
|
|
03/31/2021 12:00:37
|
0
|
3.2
|
0.00673278
|
|
03/31/2021 12:00:38
|
0
|
2.6
|
0.00445774
|
TGHT Voltage and TGHT current are both read from the same PLC module, which tells me that the PLC module is not likely the issue since we were still reading other signals when IGP was reading 0.
For the new update, I adjusted the delay to 5 seconds since the signal drop seemed like it was about 2s and was enough to lose the IGP STATON bit which tripped TGHT.
The delay only applies for the STATON status which can also be described as reading OK status in this case. Any other trip will be instantaneous and work as normal.
STATON is “ANDed” with other trips. i.e. IEVAPIGP_LESS10MTORR = IEVAPIGP1_RDVAC < 10mTorr AND IEVAPIGP1_STATON."
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