Two properties One Node FAIL, two nodes OK

[CoastalMaineBird]

LV 2010, PXI, EtherCAT 9144

I'm working on configuring EtherCAT modules from code, rather than from LV project settings  (need to have dynamic configuration options).

If I start with MOD1 CH0 configured(from the project) as a Thermocouple, this code works.  But it doesn't CHANGE the channel's mode.

If I start with MOD1 CH0 configured(from the project) as VOLTAGE or anything else, this code fails will error 65720.

But it succeeds if I do the same thing in two separate nodes:

If the property really is "not valid for this module", then why wouldn't it fail every time?

Why would it fail only if it changes the value of a setting?

And why does doing the same thing in TWO nodes succeed, where doing it in ONE fails?

[JoeySpinella]

Hi Steve,

Thanks for posting this discrepancy. 

The error code 65720 is a general error code that includes the property not being valid for the module OR for the way the module is currently configured. It seems like it is required to set the the Range Mode to Thermocouple before we can specify the units of the degrees. This makes sense to me, since if we were to set the Range Mode to Voltage, the "Degree" property would no longer apply. Therefore we need to use two separate property nodes to first set the Range Mode and then specify a subproperty of that node. While Property Nodes with multiples elements operate sequentially, in this case for some reason that does not seem to work.

Good luck!

[CoastalMaineBird]

While Property Nodes with multiples elements operate sequentially, in this case for some reason that does not seem to work.

I can understand the need for sequential operation. But it's provided in theory, by the property nodes top-to-bottom organization.

Like the old maxim says:  "In theory, theory and practice are the same.  In practice, theory and practice are different."

Tech support pointed me to this paper, stating that it's a known issue that was fixed in LV 2012 / NI RIO 12.0

[JoeySpinella]

Hi Steve,

Sorry I failed to catch that the first time! Good catch on your end, this definitely was the issue addressed by Corrective Action Request #327361, which was fixed for the release of LabVIEW 2012.

Please don't hesitate to reach out to us in the future with potential bugs, these are very helpful to us if we don't already know about them!

[CoastalMaineBird]

 don't hesitate to reach out to us in the future with potential bugs

If you know my history, you know that I have no such hesitation.  I'm thinking my mugshot may be posted on NI campus walls....

😉