Thread: Multiple Channel Guided Calibration for PNA

Hi, thanks for reading this.....

I am writing some software in Visual Basic, using COM. I have got most of the things I want to do pretty well sorted out OK. I am setting up between 2 and 8 measurements depending on user input and then calibrating in 1 of 3 ways. I can do the Ecal calibration OK. However, I am struggling with a mechanical standards calibration, where I am trying to acquire each standard for all channels in one go to minimise the number of connector swaps needed.

The analyser is an E8801A PNA. Application code is A04.87.01 / build 450.0 / Type Library 1.9. It is an older windows 2000 machine and I think that this is the latest version available to me.

The VB code I have is:

Set calmgr = pna.GetCalManager
Set guidedcal = calmgr.GuidedCalibration

For c = 1 To NumberOfChannels

pna.ActivateWindow c
Set chan = pna.Channels(c)

Set CalSet = calmgr.CreateCalSet(c)
calsetGUID(c) = CalSet.GetGUID
chan.SelectCalSet calsetGUID(c), True
guidedcal.Initialize c, False

guidedcal.ConnectorType(1) = "Type N (50) female"
guidedcal.ConnectorType(2) = "Not used"

guidedcal.CalKitType(1) = "85032F"

numsteps = guidedcal.GenerateSteps

If numsteps 3 Then
scrap = MsgBox("ERROR !!", vbCritical) 'all channels will be open / short / load
Exit Sub
End If

Next c

For calstep = 1 To 3
scrap = MsgBox(guidedcal.GetStepDescription(calstep), vbOKOnly, "Step " + CStr(calstep) + " of 3")

For c = 1 To NumberOfChannels

pna.ActivateWindow c
Set chan = pna.Channels(c)
Set meas = pna.Measurements(c)
chan.Continuous
meas.Activate
calmgr.GetCalSetByGUID calsetGUID(c)
chan.SelectCalSet calsetGUID(c), True
guidedcal.AcquireStep (calstep)
chan.Hold True
Next c
Next calstep

For c = 1 To NumberOfChannels
Set chan = pna.Channels(c)
pna.ActivateWindow c
Set meas = pna.Measurements(c)
chan.Continuous
meas.Activate

calmgr.GetCalSetByGUID calsetGUID(c)
chan.SelectCalSet calsetGUID(c), True
guidedcal.GenerateErrorTerms
chan.Hold True
Next c

This almost works, but when it gets to the point of generating error terms, there is an error saying error terms could not be applied. The very last channel does seem to have correction applied, and I think that the problem is that the proper cal set is not being selected at each step. This makes me think that the command "calmgr.GetCalSetByGUID calsetGUID(c)" and "chan.SelectCalSet calsetGUID(c), True" is not working as I think it should.

So, am I missing something (obviously, I am!!) or is there a bug in this old analyser that is preventing me from doing what I want?
There is very little information on the forum about multiple channel calibrations and what there is uses SCPI.

Can anybody help? thanks for any ideas you may have,

Best regards, Mike.

Thanks, Dr_joel

I've been out of the office for a few days, so hence the delay in my reply. I will try the SCPI parser idea; thanks for that. All the cal sets definately get created, but it is only the last of the set that seems to get any "action".

I'm writing this software very much as an asside to my core job, so progress is a bit slow, but when I get chance to do a bit more I will report back.

Thanks agian,
Regards, Mike.