6541 - problems with examples

[Zackivan]

I'm trying to get my 6541 up and running, however, I am having trouble with the examples provided with the niHSDIO Labview software. The main problem is with the the Generation Voltage selection. When ever I select a specific voltage, like 0, on say the 'Static Generation And Aquisition.vi' I receive the following error:

Driver Status:  (Hex 0xBFFA0010) Invalid value for parameter or property.

Property: Trigger Voltage Low Level
You Have Requested:  0.000000
You Can Select:  900.0 e-3,  1.250000,  1.650000

Status Code: -200077

Then when I select one of the suggested voltages, in this case 1.25V, I receive the following error:

Driver Status:  (Hex 0xBFFA0010) Invalid value for parameter or property.

Property: Data Voltage Low Level
You Have Requested:  1.250000
You Can Select:  0.000000,  0.000000,  0.000000

Status Code: -200077

As you see, you end up back where you started.

Someone help, I need to get out of this loop.

Zack

[Ryan_M]

Zack,

I notice that the first error message you posted below has a property value = "Trigger Voltage Low Level".  If this is the case then the problem may be that the diagram was editted such that the configuration voltage vi is not setting the correct property.  Make sure that both the generation and acquisition voltage vi's are configuring the "Data Voltage Levels" or "Data Voltage Family" and NOT the "Trigger Voltage Levels".

The "Static Generation and Acquisition.vi" example as shipped with LabVIEW uses the Custom Levels version of the Configure Voltage VI.  If you look on the diagram of the example, you should see a drop down box under the two voltage configuration VI's (one for generation one for acquisition).  In this drop down option, you can alter the configuration type to "Logic Families".  In this fashion, software will pick the correct values for you.  Since the NI 6541 is a selectable voltage device, the "Logic Families" is the easiest way to configure voltage levels.

However, that's not to say you cannot use the "Custom Levels" version, you just have to make sure you input valid values.

For generation voltage levels, the NI 6541 and 6542 supports values of 1.8, 2.5, and 3.3 for the "high level" input and only a value of 0 for the "low level" input.  For acquisition, both high and low inputs must be the same and must be equal to 0.9, 1.25, and 1.65.  You'll notice that these acquisition voltage levels are half of the allowed values for generation.  The generation and acquisition levels are independently controlled so you could generate a 1.8V signal and acquire using a 1.65V threshold.  There is significantly less noise immunity margin in doing this but it is a valid option for you.

So, for example, looking at the "Static Generation and Acquisition.vi" front panel, the code should run correctly given that:

Generation Voltage High = 3.3, 2.5, 1.8
Generation Voltage Low = 0

Acquisition Voltage High = 1.65, 1.25, 0.9
Acquisition Voltage Low = Acquisition Voltage High

Hope that helps!

-RyanMosley

Message Edited by Ryan M on 01-11-2006 01:03 PM

[Zackivan]

Thanks, I didn't realize that the high and low aquisition voltage had to be the same. You saved the day!

Zack