Reading Local Variable from Micro820

[mglowinski93]

Hi,
i'm trying to read local variable from Micro 820, but i'm getting error:

Analog value: 0
Digital value: False
Traceback (most recent call last):
  File "C:/Users/mglow/Documents/Projects/RaspberryPi And Rockwell Communication/Python/main.py", line 11, in <module>
    own_value = comm.Read('Program:MAIN.MyOutput')
  File "C:\Users\mglow\Documents\Projects\RaspberryPi And Rockwell Communication\Python\venv\lib\site-packages\pylogix\eip.py", line 90, in Read
    return _readTag(self, tag, count, datatype)
  File "C:\Users\mglow\Documents\Projects\RaspberryPi And Rockwell Communication\Python\venv\lib\site-packages\pylogix\eip.py", line 203, in _readTag
    InitialRead(self, t, b, dt)
  File "C:\Users\mglow\Documents\Projects\RaspberryPi And Rockwell Communication\Python\venv\lib\site-packages\pylogix\eip.py", line 1506, in InitialRead
    raise ValueError('Failed to read tag: {}'.format(err))
ValueError: Failed to read tag: Path destination unknown

Process finished with exit code 1

Python code:

from pylogix import PLC
from socket import timeout # This is raised when no connection with PLC

with PLC() as comm:
    comm.Micro800 = True
    comm.IPAddress = "192.168.178.58"
    analog_value = comm.Read('_IO_EM_AI_00')
    print(f'Analog value: {analog_value}')
    digital_value = comm.Read('_IO_EM_DI_00')
    print(f'Digital value: {digital_value}')
    own_value = comm.Read('Program:MAIN.MyOutput')
    print(f"My own value from SUBPROGRAM: {own_value}")

On Micro 820 i've created a Program MAIN and inside local variables "MyOutput".

I will be grateful for all tips related to this problem:)
btw. i've seen #8, but there is no clear answer

[dmroeder]

Unfortunately, there is no way to read local variables, Rockwell doesn't provide a way. You can only read global variables.

[mglowinski93]

At least it is clear now. Thanks for reply.

[evaldes2015]

Is this issue specific to the Micro820? Because I can read program locals on an CompactLogix.

[dmroeder]

This is specific to the Micro820 and 850.

[mglowinski93]

I can ask Rockwell Directly (i'm cooperating with them very often), if you tell me what to ask about.

[bashiryousufy]

@mglowinski93 Did you find a way to read local variable?

[mglowinski93]

@mglowinski93 Did you find a way to read local variable?

No, i didn't.

[bashiryousufy]

@mglowinski93 Did you find a way to read local variable?

No, i didn't.

Did you find any alternatives?

So basically I want to be able to read counter data and also be able to reset the counter using this package. Do you think its possible?

Note: Using Mirco820 PLC

[mglowinski93]

@mglowinski93 Did you find a way to read local variable?

No, i didn't.

Did you find any alternatives?

So basically I want to be able to read counter data and also be able to reset the counter using this package. Do you think its possible?

Note: Using Mirco820 PLC

No, I did not.
I simply mapped local variables to global ones, it was enough in my case.

[bashiryousufy]

@mglowinski93 Did you find a way to read local variable?

No, i didn't.

Did you find any alternatives?
So basically I want to be able to read counter data and also be able to reset the counter using this package. Do you think its possible?
Note: Using Mirco820 PLC

No, I did not. I simply mapped local variables to global ones, it was enough in my case.

Any tips on how to achieve the mapping?

[mglowinski93]

@mglowinski93 Did you find a way to read local variable?

No, i didn't.

Did you find any alternatives?
So basically I want to be able to read counter data and also be able to reset the counter using this package. Do you think its possible?
Note: Using Mirco820 PLC

No, I did not. I simply mapped local variables to global ones, it was enough in my case.

Any tips on how to achieve the mapping?

I simply used the COPY instruction.