Write a boolean as an element of a DINT

[JacobsCSD]

I'm trying to use pycomm3 to write a single boolean value into a byte of a DINT. I tried treating the DINT as an array of booleans, but that did not work.

The library returns the following error:
Tag=RMT_IN.CYL.Status.3, Error=Destination unknown, class unsupported, instance undefined or structure element undefined (see extended status) - Extended status out of memory (05, 00)

I am writing this boolean as a part of writing several tags using the tuple method.

I am using the LogixDriver on an A/B PLC. Please let me know if you need specifics on the PLC.

[ottowayi]

What is the PLC and version you're using? This is supported and should work, there are tests for it and I just tried it myself without any issue. Also, check the permissions on the tag to make sure it's not None or Read Only.

>>> with LogixDriver('192.168.1.236') as plc:
...     plc.write('write_udt1.dint.0', 1)
...
Tag(tag='write_udt1.dint.0', value=1, type='BOOL', error=None)
>>> with LogixDriver('192.168.1.236') as plc:
...     plc.read('write_udt1.dint.0')
...
Tag(tag='write_udt1.dint.0', value=True, type='BOOL', error=None)

[JacobsCSD]

@ottowayi,

Sorry for the delay in responding!

I worked with my PLC programmer to test a couple of things out. With Pycomm3 I can write to a single bit of a DINT embedded within a UDT, as you stated above. The library is giving me the error I mentioned in my original post because RMT_IN is a UDT and CYL is an embedded UDT inside RMT_IN. Status is a DINT within CYL, i.e. attempting to read or write RMT_IN.CYL.Status.0 gives me the Destination unknown error.

I was able to read RMT_IN.CYL.Status as a DINT.

We are using an AllenBradley 1756-L83E PLC with Studio 5000 version 32 or 33.

[ottowayi]

Ohh I understand now, sorry I was able to replicate it and it is a bug. I think I found the fix and it was a dumb mistake that's really easy to fix. So if you want to try it out: in pycomm3/logix_driver.py on ln 1333, the join should be a period and not an empty string, like:

I need to add some more tests to cover this and another issue I fixed, so it might be a couple days before I have time to get it released. But it should be out soon, I'll post back here when I publish it.

[JacobsCSD]

@ottowayi

Thank you for the help! That change to line 1333 in logix_driver.py fixed my issue. I look forward to the update that includes that fix.

Thank you!
@JacobsCSD

[ottowayi]

Issue fixed in v1.2.3