Data logging in PLC help!!

[hazemabdulrab]

Being nosey, what r u planning on doing with your big stack of numbers in the plc? I only ask because you mentioned you were also getting FTView which would do the data logging thing for u ?

I was thinking of displaying it on the hmi.so when the quality engineer wants to see who built the door . he would out in the serial number and search for it. when he finds it it will pull up the operator , serial number, date/time, and anything that might have been bypassed.

I was going to add a file search and compare instruction to find the serial number and move it to the hmi display along with other info connected to that serial number.

How would have displayed it ?

 

[hazemabdulrab]

after the FFU unloads the fifo and it automatically shifts up all the data bytes. Does it clear the .dn bit and subtract 1 from the positon value of the FFL?

 

[Mike_RH]

How important is this data?
If it is kept in the PLC, the data is gone if the PLC looses its memory,or if the project is downloaded again, or . . .
Log the data in a HMI / SCADA system to get it out of the PLC.

My 2 cents.

 

[xC0MMAND0x]

How important is this data?
If it is kept in the PLC, the data is gone if the PLC looses its memory,or if the project is downloaded again, or . . .
Log the data in a HMI / SCADA system to get it out of the PLC.

My 2 cents.

Agree.

I wouldn't use a PLC as a database storage logging data for 20 days, or even 1 day for that matter. I would use the right tool for the Job. If you have an HMI / SCADA implementation I would use that.

 

[Lancie1]

After the FFU unloads the fifo and it automatically shifts up all the data bytes, does it clear the .dn bit and subtract 1 from the positon value of the FFL?

After doing an Unload (of a full FIFO resiter), the DN bit (ON when Position = Length) will go OFF until after the next Load, when Position will again = Length.

If you only have say 9000 Serial Numbers in your 18000-Length FIFO memory stack, then each time you do either a FFL or FFU, the DN bit will NOT go ON. If your FIFO is empty (Position = 0), then the EM bit will be ON. Each time a FFL is triggered, the EN bit goes ON, and each time a FFU is triggered, its EU bit goes ON.

Yes, the Position value is always updated automatically to show how many data points are in the FIFO memory stack.

If it is kept in the PLC, the data is gone if the PLC looses its memory...

Many PLCs now have a non-volitile memory area that is not gone on power loss. I think the last 20 days of serial numbers is going to be changing rapidly in this case, so maybe it is not worth the effort to keep doing backups. No doubt the company will have paper records of all parts shipped out anyway.

 

[Lemming]

I think I would do it without using the FFL / FFU.. Would be simplier to just increment a position index value, and enter the "1" new set of values on that indirection. Once @ 18000, roll back to start and over write. This way no thought is necessary on unloading...Seems like you will need several arrays to handle relevant data, date / time, user & serial number..

Only down side is the array wont always be oldest to newest data, but if you are using a FSC, wont matter...

 

[Lancie1]

Would be simplier to just increment a position index value, and enter the "1" new set of values on that indirection.

For you but not for me. Different solutions for different folks. For me, I like a nice built-in factory-made, well-tested, well-documented all-in-one instruction that takes care of the housekeeping chores such as sorting the data from oldest to newest without me having to lift a finger.

All I have to do is read the manual and learn how to use it for my full advantage.

 

[Lemming]

For you but not for me. Different solutions for different folks. For me, I like a nice built-in factory-made, well-tested, well-documented all-in-one instruction that takes care of the housekeeping chores such as sorting the data from oldest to newest without me having to lift a finger.

All I have to do is read the manual and learn how to use it for my full advantage.

fair enough

 

[V0N_hydro]

I have used data logging in the PLC where communications to the PLC from the HMI software has been over a multi hop solar/wind powered wireless network which was subject to an outage or two per year.