maexio
Lifetime Supporting Member
So this is a weird issue and its really a stretch to guess what is happening.
We have what is known as a lug chain, which is basically a continuous chain with attachments on it. It is driven by a K5700 servo drive with Scaling set 0-100 per attachment 'lug space'.
We have an event task that is being fired on forward only transition to 0 from the k5700.
In the event task we Cop ScannerLC[0] ScannerLCTmp[0] 100
then COP ScannerLCTmp[0] ScannerLC[1] 99
then FLL 0 ScannerLC[0] 1
There are no other mass cop instructions with a length greater than 1 in the plc, or FLLs, or Clrs and ScannerLC[0] is set to Read Only for external access.
What appears to be happening is that the system clears all values for ScannerLC[0] -> ScannerLC[26] inclusive, Randomly.
This is a startup so the system is just getting into spring / summer weather in Missouri, and the panel appears to be getting quite hot (100f output temp).
Last night we powered down the whole system and it started up this morning fine. It ran for about 3 hours this morning without issues, then the exact same issue started happening (no changes to code during this time), and we opened the panel to check the temperature (letting out some of the hot air) and it has stopped happening. Since then it has rained, so the overall temperature is a little lower, and the problem is not happening.
This sounds stupid to suggest temperature could cause a random change to the data, but we haven't seen any other correllations that make sense.
Processor is a 1756-L83E, and the ethernet network has been clean all day (no errors / faults, etc).
Last night we tried turning off produced / consumed tags (in case this was happening), and it still occurred.
The really odd part is that there are 4 lug chains that are cammed together and moving data, but the ScannerLC is the only array this is happening to. It is also the highest priority number of the event tasks, so not sure if that is a coincidence or not.
Let me know if more info is needed..
We have what is known as a lug chain, which is basically a continuous chain with attachments on it. It is driven by a K5700 servo drive with Scaling set 0-100 per attachment 'lug space'.
We have an event task that is being fired on forward only transition to 0 from the k5700.
In the event task we Cop ScannerLC[0] ScannerLCTmp[0] 100
then COP ScannerLCTmp[0] ScannerLC[1] 99
then FLL 0 ScannerLC[0] 1
There are no other mass cop instructions with a length greater than 1 in the plc, or FLLs, or Clrs and ScannerLC[0] is set to Read Only for external access.
What appears to be happening is that the system clears all values for ScannerLC[0] -> ScannerLC[26] inclusive, Randomly.
This is a startup so the system is just getting into spring / summer weather in Missouri, and the panel appears to be getting quite hot (100f output temp).
Last night we powered down the whole system and it started up this morning fine. It ran for about 3 hours this morning without issues, then the exact same issue started happening (no changes to code during this time), and we opened the panel to check the temperature (letting out some of the hot air) and it has stopped happening. Since then it has rained, so the overall temperature is a little lower, and the problem is not happening.
This sounds stupid to suggest temperature could cause a random change to the data, but we haven't seen any other correllations that make sense.
Processor is a 1756-L83E, and the ethernet network has been clean all day (no errors / faults, etc).
Last night we tried turning off produced / consumed tags (in case this was happening), and it still occurred.
The really odd part is that there are 4 lug chains that are cammed together and moving data, but the ScannerLC is the only array this is happening to. It is also the highest priority number of the event tasks, so not sure if that is a coincidence or not.
Let me know if more info is needed..