Return data gets jumbled up on a multi write when the tags don't exist.

[Destination2Unknown]

Code

from pylogix import PLC

with PLC() as comm:
    comm.IPAddress = "192.168.1.9"

    write_data = [("tag1", 100), ("tag2", 6.45), ("tag3", True)]

    # write the values
    ret = comm.Write(write_data)

    # print the status of the writes
    for r in ret:
        print(r.TagName, r.Status)

Prints:

tag2 Unknown error timed out
6.45 Unknown error timed out

Versions

• pylogix: 0.8.11
• python: 3.11
• OS: Windows

[dmroeder]

I have a fix for this.

[Destination2Unknown]

@dmroeder Sweet!

[Destination2Unknown]

I think this was the issue:

https://github.com/dmroeder/pylogix/blob/95d6bc9413cb5d7f54eb231a802dd9f2d3950e08/pylogix/eip.py#L435-L436

It should be something like:

if not conn[0]:
    return [Response(t[0], None, conn[1]) for t in tags]

[dmroeder]

You mind testing the bugfix/multi-write branch when you get time? It works for me, though things weren't quite failing in the same way for me.

[Destination2Unknown]

Pretty much sorted, only case where it didn't work was where the tags don't exist and there is no connection to the PLC (i.e. if the IP Address is incorrect):

from pylogix import PLC

with PLC() as comm:
    comm.IPAddress = "192.168.133.199"

    write_data = [("tag1", 100), ("tag2", 6.45), ("tag3", True)]

    # write the values
    ret = comm.Write(write_data)

    # print the status of the writes
    for r in ret:
        print(r.TagName, r.Status)

prints:

tag2 Unknown error timed out
6.45 Unknown error timed out

https://github.com/dmroeder/pylogix/issues/224#issuecomment-1540346196

[Destination2Unknown]

This fairly niche example isn't quite right either...

write_data = [("myDint", 100), ("myString", "Hello"), ("myDint.1", True)]

# write the values
ret = comm.Write(write_data)

# print the status of the writes
for r in ret:
    print(r.TagName, r.Value, r.Status)

prints:

myDint 100 Success
myString Hello Success
myDint.1 (2, -1) Success

[dmroeder]

Yeah, that is weird. The latest should fix it.

[Destination2Unknown]

Yeah, that is weird. The latest should fix it.

This case is still incorrect:

from pylogix import PLC

with PLC() as comm:
    comm.IPAddress = "192.168.133.199" #incorrect IP address

    write_data = [("tag1", 100), ("tag2", 6.45), ("tag3", True)]

    # write the values
    ret = comm.Write(write_data)

    # print the status of the writes
    for r in ret:
        print(r.TagName, r.Status)

prints:

tag2 Unknown error timed out
6.45 Unknown error timed out

[dmroeder]

I see, somehow, I missed that comment originally

[dmroeder]

Okay, that one should be fixed on that branch too.

I considered whether to return the value that was written or the None. I went with value intended to write because that is what would be returned on a successful write. Though I could be convinced otherwise.

[Destination2Unknown]

Okay, that one should be fixed on that branch too.

I considered whether to return the value that was written or the None. I went with value intended to write because that is what would be returned on a successful write. Though I could be convinced otherwise.

I strongly favour returning None because it would make it crystal clear that there was an issue. Otherwise, it could lead to confusion when a write value is returned despite not being sent successfully.

Thank you for your assistance. This library is exceptional, and the support provided is truly outstanding!

[dmroeder]

Sold! I'll return None. I appreciate your feedback and testing.

[Destination2Unknown]

Looks good to me, thanks again!