Hello, we are currently using a PCIe-DAS1602/16, along with the API it came with for a project. There are some peculiar behaviors involving the DAQ that I wanted to ask about and see if anyone knows the fix.
From what I understand, the DAQ was originally in its out of box state, just plugged into a PC. I know there is a calibration tool in InstaCal, but I will touch more on that later. For the API, we used the included C code, that was ported up to C++.
To begin, we had some issues reading voltages using the cbVIn() call. We did eventually get it to work, but only when configure to bipolar +/- 10 volts mode. We only need unipolar 5 volts, however that configuration never gave any readings. We did move the jumpers on the card, change the settings in InstaCal, and make the appropriate calls in software accordingly when we tried other modes. We did get some reading in other modes like bipolar 5 volts, but results were very odd, as it was appearing to distort waveform or have strange edge detection.
In bipolar 10 volts, we get voltage readings, but they float around a lot and are not accurate. E.g. 5 volts reads as 7.3 volts and if left being monitored it will skew up to 10 volts. Voltage and skew directions are sometimes random
When monitoring more than one channel, like two or 3, each channel seems to affect another, as they skew differently opposed to being monitored alone.
When monitoring 4 channels, they seem to stabilize each other, as the skewing becomes minimal and hovers around a value
I figured this could very well be due to the fact that the card is not calibrated. I attempted do some of the calibration options in InstaCal, but I didn’t have any luck there. In the A/D configuration, I couldn’t get the sliders to move with the potentiometers. On top of that, I the notifies you that if you reach the end of the adjustment range of a pot, close the app, go all the way back to the other limit and try again, but the pots I attempted to adjust appear to be infinitely free spinning with no limits in either direction. Is this normal? Also, due to the limited equipment we have in this nature, I attempted to use the output of the digital pins using cbDout() for the calibration, as well as the ground.
I mostly want to know what causes the floating and skewing voltage reading, and if there is a way I can fix that. Also, I want to know if the free spinning potentiometers is normal, or if there is something wrong with the card, as it makes calibrating the card confusing.
Note: this was originally an email to Measurement Computing's support email. They replied telling me to post it here, so hopefully this is correct
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DJQ
Hello, we are currently using a PCIe-DAS1602/16, along with the API it came with for a project. There are some peculiar behaviors involving the DAQ that I wanted to ask about and see if anyone knows the fix.
From what I understand, the DAQ was originally in its out of box state, just plugged into a PC. I know there is a calibration tool in InstaCal, but I will touch more on that later. For the API, we used the included C code, that was ported up to C++.
To begin, we had some issues reading voltages using the cbVIn() call. We did eventually get it to work, but only when configure to bipolar +/- 10 volts mode. We only need unipolar 5 volts, however that configuration never gave any readings. We did move the jumpers on the card, change the settings in InstaCal, and make the appropriate calls in software accordingly when we tried other modes. We did get some reading in other modes like bipolar 5 volts, but results were very odd, as it was appearing to distort waveform or have strange edge detection.
In bipolar 10 volts, we get voltage readings, but they float around a lot and are not accurate. E.g. 5 volts reads as 7.3 volts and if left being monitored it will skew up to 10 volts. Voltage and skew directions are sometimes random
When monitoring more than one channel, like two or 3, each channel seems to affect another, as they skew differently opposed to being monitored alone.
When monitoring 4 channels, they seem to stabilize each other, as the skewing becomes minimal and hovers around a value
I figured this could very well be due to the fact that the card is not calibrated. I attempted do some of the calibration options in InstaCal, but I didn’t have any luck there. In the A/D configuration, I couldn’t get the sliders to move with the potentiometers. On top of that, I the notifies you that if you reach the end of the adjustment range of a pot, close the app, go all the way back to the other limit and try again, but the pots I attempted to adjust appear to be infinitely free spinning with no limits in either direction. Is this normal? Also, due to the limited equipment we have in this nature, I attempted to use the output of the digital pins using cbDout() for the calibration, as well as the ground.
I mostly want to know what causes the floating and skewing voltage reading, and if there is a way I can fix that. Also, I want to know if the free spinning potentiometers is normal, or if there is something wrong with the card, as it makes calibrating the card confusing.
Note: this was originally an email to Measurement Computing's support email. They replied telling me to post it here, so hopefully this is correct
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