What would cause an Error In when there is no Error sent forward?

[ImpInTraining]

This is only part of the VI that I have planned.  There are two signal generators in operation.  The top line talks to the Agilent SG, where the error is being generated.  The bottom VISA line talks to our Rohde & Schwarz SG and has no problems.  Eventually, I have to work a spectrum analyzer in there too.  I hadn't even begun to think about how to work the error line in to one output.  

I traced this program through, and there was no error after setting the power level going down the line.  Then, suddenly on the input of the RF Power On Sub-VI, it has an error in.  This is before it even talks to the equipment, right?  So I'm a little confused at the suggestion that the instrument is creating the error.  Why wouldn't it have shown up in either of the two previous subVIs which talk to the same instrument?

[ImpInTraining]

Thanks for the suggestion, wired in a constant prior to the initialization VI for Error In.  And I changed the lines over to shift registers, but it didn't matter.  Nothing changed.  One thing I did notice which was quite peculiar was that even with the shift register in error on the right, it came across as OK on the left until it hit that same RF Power On sub-VI again.  I thought it it had an error, it'd pass it forward to the left shift register.

[Dennis_Knutson]

To quote what you already posted - "The error listed comes across as code -1074000000,  -113, "Undefined header +0, "no error""

The error code and message tell you that it is coming from the instrument. Read the manual and look up code -113. Read the description for --1074000000.

[ImpInTraining]

"The header is syntactically correct, but it is undefined forthis specific device. For example, *XYZ is not defined forany device."  How do change the header then to make it right?

[Dennis_Knutson]

First find out which function causes the instrument to generate the error. I have not downloaded the driver so I have no idea which functions do an instrument error query. I would suggest doing the debug with just the code for the one instrument.

[ImpInTraining]

I have put all the equipment in a single chain for Error message passing, and it had no change.  I also found out why the shift register wasn't working.  Seemed it was over-top of the tunnel that was actually being used.  That's so deceptive sometimes.  

[ImpInTraining]

The following attachments are the Configure RF Output - which produces the error in the chain, and Error Query - which is a Sub-VI of Configure RF Output where the error is generated.

Funny thing is, when I run Error Query solo, there is no error.

[Dennis_Knutson]

Running Error Query by itself should not cause an error. When you run it as part of the higher level VI, it gets the complete error queue from the instrument. Run error query again and since the queue is empty, no error is reported.

The Configure RF Output has 5 subVIs. Run each one separately and after each, call the error query. This is try to isolate what is causing the error.

[ImpInTraining]

No joy.  Very uninformative as it says there are no errors after each of the sub-VIs run individually.  

I've ran the equipment through a thorough self-test, and it passed everything.

[Dennis_Knutson]

And if the configure function still generates the error, you've isolated it to the other SCPI statements in the VI.