4248a Issues

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Joined: Fri Feb 23, 2024 12:54 pm

4248a Issues

Post by JamesW2 »

I’m developing LabVIEW software for an automotive test rig that will feature x6 4824A’s and I’m having issues getting them to function correctly. The rig has a LabVIEW DAQ and several IO board’s so the application needs to run on multiple cores via multiple while loops running concurrently. This is the way serval previous rigs not using Picoscopes have been written and works adequately this other automotive hardware communicating via modbus and XCP. The Picoscope examples don’t lend themselves to running multiple calculation cycles and I’ve had issues combining them and running over multiple cycles.
Initially the test rig was manually used without LabVIEW for one Unit Under Test with one 4824A connected to the Picoscopes 6 software. The specification for the rig has the LabVIEW IO controlling hardware to get the 6 Unit Under Tests to a predefined condition, this involves heating controlled via the LabVIEW software and adds the requirement to hang the software at any time. Then the first Picoscopes sign wave generator is used to trigger the Unit Under Test and collect 100 cycles of the signal generator. The other 5 Units under test are then tested one after another. Next the LabVIEW IO is used to get to the next test point and then the Units Under Test are tested in order again. This repeats for multiple test points with multiple log files being generated, analysed and Excel reports being generated.

My Issues are:
1. PS4000_Open hangs all the LabVIEW threads running, is there a way to stop this and only hang the thread it is running on? This has been the behaviour of all the other hardware used with LabVIEW before.
2. When I try to run Rapid or Block capture over multiple cycles it works fine for the first time and after that PS400aIsReady reports the data has been captured but PicaStBuffer returns empty arrays. The method I have used to do this is to split the example logic via multiple cases in a case structure creating a state machine, the handle and error are then updated and passed back into the case each step. PS4000Open is the first state, followed by an idle mode, the rest of the rapid block capture example minus the close and finally the PS4000Close block. Each mode is then entered via push buttons in the GUI, this allows the following run order, Open, Idle, Capture, Idle, Capture, Idle, Close. Is there a way to get the data from the buffer?
3. When combining the AWG and Rapid block example I have been unable to capture every cycle generated by the signal generator trying multiple configurations. What is the best way to setup the capture and then enable the signal generator?
4. In Picoscope 6 the signal generator has the option to configure the “Cycles Per Trigger” when Tigger Source is Manual. Is the same possible with the LabVIEW Blocks when trigger source is set to software?

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Joined: Tue Oct 21, 2014 3:07 pm

Re: 4248a Issues

Post by AndrewA »

Hi, Please email us directly at support@picotech.com and we help resolve these issues.
Regards Andrew
Technical Specialist

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