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Samba SM43 - 4 - 20mA input issue


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9 minutes ago, Ausman said:

Great response, all there.  The O/S update all went though OK to the very end?  Perhaps pull the battery for an hour and reinsert?  Shouldn't make any difference, though.

Something weird going on, vot haf u done, munchkin?!!

Time for thinking caps and pondering....will advise.  The different boot and O/S numbers bother me....comments and research needed.

cheers, Aus

I try to be as complete as possible, since I am dealing on a daily basis with complaints which say "such and such is not working properly". And then it takes forever to get all the info, like "what did you do? What happened? Was there noise / smoke? etc"....

Yes, update went all the way through without any error / warning. Battery is out at the moment.

4 minutes ago, Ausman said:

I'd perhaps be trying to get the O/S and boot back to what they were.  But before that, download a simple program that will react to physical inputs and give physical outputs without any screen interaction, and see if the plc is working those responses correctly.  If so, then that points to there being something fundamentally wrong with the screen.

cheers, Aus

Created a program which uses SB3 to control O0 and I1 to control O1 .  (See attached)

Works without a problem...

I think there is something wrong with the screen for sure. Maybe just a bad solder connection somewhere on the board, so it looks to me like a DOA. 😞 My issue is that I am on a ship, and I am only once a week on a Saturday in a port where I can deal with shipping things back etc. So for me the quickest turn around time for something like this is 2 weeks. But all depending on my supplier. Can easily become 4 - 6 weeks 😞

So I am hoping there is a way to rectify this issue without shipping it back...

 

Thanks for all the help so far.. Dinner time here!

simple.vlp

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The "original" program which was running I deleted, but the program attached is very similar. It is very simple / basic (and messy 🙂 ) but I will rewrite it all soon when I am done learning..! haha

I am trying to figure a few things out while waiting to get the (most likely) HW problem to be resolved... I will just start another thread for these questions I think 🙂 Because this is not really about a 4-20mA input issue anymore! 

compressor test.vlp

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  • MVP 2023

Thank you for posting your code.

For starters, why are all your setpoints on the config display float data types?  They're not used anywhere else in the program.  I think you may be entering data here and then wondering why the logic isn't working, as you have duplicate names starting at net 24 (MI 4 is Setpoint 1 x 100).  It's much better PLC programming practice to use implied decimals.  For example, if you use a decimal place of 2 on the display of MI 4 the PLC will automatically add additional digits - a value of "100" will display "1.00".

In your code as is, all the setpoints (including the stop setpoint) are probably zero causing your outputs to race around in a circle like a bunch of squirrels on coffee.

On your trend, Y max should probably be 3200.

This is why we always ask people to post their code.  Please listen next time - Cam asked this early on.

Anyway, load this and see what happens.

 

Joe T.

 

compressortest JT.vlp

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10 hours ago, Joe Tauser said:

For starters, why are all your setpoints on the config display float data types?  They're not used anywhere else in the program. 

Thanks for looking into the code. This part of the code was written when I had no access to the PLC (since it hadn't arrived yet), and I was just trying things out. My idea was to convert the floats to ints later on.

10 hours ago, Joe Tauser said:

It's much better PLC programming practice to use implied decimals.  For example, if you use a decimal place of 2 on the display of MI 4 the PLC will automatically add additional digits - a value of "100" will display "1.00".

I was not aware of this. This is my first time trying to program a PLC, and it is one big (interesting) learning experience for me.

10 hours ago, Joe Tauser said:

In your code as is, all the setpoints (including the stop setpoint) are probably zero causing your outputs to race around in a circle like a bunch of squirrels on coffee.

The setpoints had a power up value so I had no issue with that.

 

Unfortunately the PLC seems to have an issue with the display now, which so far couldn't be resolved by reloading OS / re-initializing the memory etc. Hopefully Unitronics support will come with a solution 🙂

 

Thanks again for your help.

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