set high input impedance on Tektroniks DMM4040

[hcastor]

I'm using a Tektroniks DMM4040 with SE to log voltage data. When the DMM is used in manual mode, there is an option for high input impedance (>10 GOhm) when measuring potentials.

Can this option be switched on when the DMM is controlled by SE ?

Thanks in advance !

marc

[Nick-A]

Hi marc,

 When you ask if the option can be switched on while the DMM is being controlled by SignalExpress, what exactly do you mean?  Are you trying to change the impedance programatically or physically?  I don't see a reason why you would not be able to change it physically while it is connected and it would be worth giving it a shot to see what happens.

Nick

[hcastor]

Hi Nick

thanks for the reply.

I was wondering if there is a way the high impedance can be switched on by SE.

When the DMM is not in 'local' mode (i.e. it is communicating with SE), the 'Measurement Setup' Button on the DMM Front Panel is disabled, so 'High input impedance' cannot be set on the DMM. If the option is switched on while still in local mode and then a communication is established between the DMM and SE, the option is not turned on anymore when the DMM returns to local mode. This means to me that SE turns off 'high impedance' by default and measurements via SE cannot be carried out in high impedance mode. Is that correct ?

[Nick-A]

Hi marc,

I am not familiar with the specific hardware and Tektronix version of SignalExpress that you are using, but after playing around with SignalExpress I am able to change the input impedence within the configuration tab of my channel.  Is this an option for you?

Perhaps a screenshot of what you are able to see might be beneficial.

Nick

[hcastor]

Hello Nick

thanks for your reply.

The Channel View remains empty when Tektroniks multimeters are connected, so the only possibility to configure these instruments is via the Step Setup.

It's kind of funny when you're telling me that you aren't familiar with the hardware - because the support staff at Tektroniks keep telling me they can't help because they aren't familiar with the software and I should try to get in touch with NI who developed the code 😞

[Nick-A]

Hey hcastor,

What version of SignalExpress are you using?  

I was able to find the setting in my channel configuration.  I am not sure how you have your program set up, and a screenshot would be beneficial, but I have attached a screenshot of my own of where I see that setting.

Nick

[hcastor]

Hi Nick,

many thanks for your helpful reply -

I am using SE v2.5.1 and the most recent steps from your website.

please tell me how you open the window shown in your screenshot - as I said, my Channel View remains empty (except for the message 'No devices available'), even though the steps for my instruments are loaded and configured (i.e. I can acquire data). The only control I have is via the Step Setup.

On your screenshot I can see an option to set the measuring rate - this is another (extremely) important question I need to resolve, so it would be very helpful to know how this 'channel configuration' can be accessed.

Many thanks in advance !

marc

[Nick-A]

Hi Marc,

I apologize, that is actually the screen for the "NI-SCOPE Acquire" step.  I have checked my resources and I can't seem to find any way to change the input impedance on a DMM/Switch Acquire step.

Since we don't actually support the hardware you are using, I am not able to replicate the issue.  I was able to find this image in which someone was using Tektronix hardware with SignalExpress and changing the input impedence.  Maybe it will help.

In regards to the measuring rate, I believe this can be changed in the Timing tab.  Are you able to see this?

Nick

[hcastor]

Hi Nick

thanks for the reply.

'I was able to find this image in which someone was using Tektronix hardware with SignalExpress and changing the input impedence'

Could you post the link ?

'In regards to the measuring rate, I believe this can be changed in the Timing tab.  Are you able to see this?'

No, I've never come across a 'timing tab'...what is this and how do you access it ?

best wishes,

marc

[Nick-A]

Hi Marc,

Unfortunately it was an internal document so I am unable to share that.  There was nothing else to the issue outside of that image that I sent to you.

Can you send me a screenshot of what your program looks like?

Nick