cherokee235
Member
We have been fighting this for months. I've read several threads about this:
I also sent a query to PDQ and they answered back with the following:
The trolley will stop going to the right at the back of the vehicle for two reasons (according to CPU logic):
1. The right limit turns on (input X23)
2. The correct number of input pulses are seen from the measurement prox switch (input X30)
One of these two things is happening.
I doubt that the issue is due to a false input on the right limit. Therefore, I assume that it is an issue with the number of inputs being received from X30.
One thing that can cause the issue:
In the VT board logic, if the right limit X23 and the measure input X30 are on simultaneously (the VT tracks both inputs), then the pulse count equals 0. This usually only can occur at the right limit when the prox switch is on the flag.
However, if the VT sees this input on when the trolley is in motion, it can reset the pulse count to 0. This is usually the product of "ghosting" on the input where X30 may glow dimly due to VFD voltage in the festoon cable. A bad ground can cause ghosting as well. It only takes somewhere around 3.3 volts DC to trigger the input at the VT board.
If this happens, the trolley will be on the left of the vehicle. The VT will think that the trolley is on the right (pulse count = 0). As the trolley moves to the right, the left hand pulses will be passed through to the input X30. Normally the left pulses will not be passed through as they should be invisible to the CPU.
So, if this happens, then the trolley will stop in the middle of the bridge, the arch will rotate 270° and it will run into the back of the vehicle.
Best Regards,
PDQ Support
--------------- Original Message ---------------
From: no-reply@opwglobal.com [no-reply@opwglobal.com]
Sent: 10/20/2020 10:26 AM
To: support@pdqinc.com
Subject: Form Submission from opwglobal.com
We have tried everything suggested from the posts with no success. Every couple of days it stops early on the back and drags across the trunk or tailgate and impact switch stop. It always happens on cycle 1. Note: we tried the shielded cable from x30 sensor all the way back to JO with no success, so we replaced all our festoon cables, thereafter with the same failure results. x30 and x23 sensor and cables new. New "picket fence". New trolley rollers. New vt board. New passenger side sonic. Cleaned and remounted all ground wires. Recalibrated the vt today and numerous times before.
Today we disconnected the passenger side sonic and it measures wide when it dumps on the first pass, but when it gets to the back it measures short and drags the arch down the passenger side of the vehicle. This we can duplicate and it happened every time. This is something different. What is going on with that? I thought is would measure to the right limit with no sonic????
We reconnected the passenger side sonic and it washed fine on the test cycles. However, it may wash ok for 15 cars then measure narrow on the back and impact the bumper.
We are seeing some ghosting on x23 (right limit) which could be an issue. How can we stop that?
Also, x23 has the 4 wire cable in it from sensor to J4. I read somewhere that the 4 wire cable is inferior to the 3 wire.
X30 has the 3 wire cable.
I'm not sure where to go from here. I am concerned about x23 ghosting, and I am puzzled as to why it hit my truck every time after the sonic was unplugged.
Thanks,
David
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Hi all, I have a 9 year old laser 4000 and it has a problem that when it goes across the rear of the vehicle on the second presoak pass only, sometimes it gets half way across the back and rotates thinking it is on the right side of bridge and tries to drive forward until it gets impact switch...
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I also sent a query to PDQ and they answered back with the following:
The trolley will stop going to the right at the back of the vehicle for two reasons (according to CPU logic):
1. The right limit turns on (input X23)
2. The correct number of input pulses are seen from the measurement prox switch (input X30)
One of these two things is happening.
I doubt that the issue is due to a false input on the right limit. Therefore, I assume that it is an issue with the number of inputs being received from X30.
One thing that can cause the issue:
In the VT board logic, if the right limit X23 and the measure input X30 are on simultaneously (the VT tracks both inputs), then the pulse count equals 0. This usually only can occur at the right limit when the prox switch is on the flag.
However, if the VT sees this input on when the trolley is in motion, it can reset the pulse count to 0. This is usually the product of "ghosting" on the input where X30 may glow dimly due to VFD voltage in the festoon cable. A bad ground can cause ghosting as well. It only takes somewhere around 3.3 volts DC to trigger the input at the VT board.
If this happens, the trolley will be on the left of the vehicle. The VT will think that the trolley is on the right (pulse count = 0). As the trolley moves to the right, the left hand pulses will be passed through to the input X30. Normally the left pulses will not be passed through as they should be invisible to the CPU.
So, if this happens, then the trolley will stop in the middle of the bridge, the arch will rotate 270° and it will run into the back of the vehicle.
Best Regards,
PDQ Support
--------------- Original Message ---------------
From: no-reply@opwglobal.com [no-reply@opwglobal.com]
Sent: 10/20/2020 10:26 AM
To: support@pdqinc.com
Subject: Form Submission from opwglobal.com
| opwglobal.com |
We have tried everything suggested from the posts with no success. Every couple of days it stops early on the back and drags across the trunk or tailgate and impact switch stop. It always happens on cycle 1. Note: we tried the shielded cable from x30 sensor all the way back to JO with no success, so we replaced all our festoon cables, thereafter with the same failure results. x30 and x23 sensor and cables new. New "picket fence". New trolley rollers. New vt board. New passenger side sonic. Cleaned and remounted all ground wires. Recalibrated the vt today and numerous times before.
Today we disconnected the passenger side sonic and it measures wide when it dumps on the first pass, but when it gets to the back it measures short and drags the arch down the passenger side of the vehicle. This we can duplicate and it happened every time. This is something different. What is going on with that? I thought is would measure to the right limit with no sonic????
We reconnected the passenger side sonic and it washed fine on the test cycles. However, it may wash ok for 15 cars then measure narrow on the back and impact the bumper.
We are seeing some ghosting on x23 (right limit) which could be an issue. How can we stop that?
Also, x23 has the 4 wire cable in it from sensor to J4. I read somewhere that the 4 wire cable is inferior to the 3 wire.
X30 has the 3 wire cable.
I'm not sure where to go from here. I am concerned about x23 ghosting, and I am puzzled as to why it hit my truck every time after the sonic was unplugged.
Thanks,
David
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