We noticed that the Setpoint contact of several (so far 8 out of 14) IPCMini opens for some minutes every 32 days, although the current is well below the Setpoint. Is this a software bug?

We noticed that the Setpoint contact of several IPCMini opens for some minutes every 32 days, although the current is well below the Setpoint.

The Setpoint is 1e-5A (or 10 uA).

After waiting for more than 30 minutes with that strange behaviour, the 5 kV high voltage was switched OFF and ON again and the Setpoint contact closed as was expected.

See the video below.

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Is this a software bug?

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  • I just received confirmation that you may be correct, and a revision is in progress.

  • Dear George, thank you.

    Some time has passed, and our measurements have continued.

    Now with 12 out of 14 IPCMini, we recorded the issues with the unwanted behaviour of the setpoint contact.

    Recently, we found the clue.

    The event "setpoint contact opens" seems to happen every 49,7 days. So, for a new IPCMini one has to wait quite a long time.

    This event depends on the time, an IPCMini was connected to the 230 V mains.

    This number tells me, that there might be a 32-bit timer that counts the milliseconds. If this counter hits 2^32, then it overflows.

    Well, 2^32 milliseconds is 49,707 days.

    There should be a second counter that counts the time, that the 5 kV high voltage is on.

    Probably, this is also a 32 timer or a 32 bit variable. This also overflows, when reaching 2^32.

    The overflow of the timer for "230 V" makes the setpoint going to the wrong state.

    The overflow of the other timer "5 kV on", makes the setpoint to go back to the correct state.

    Thus, if a fresh IPCMini is taken out of the box, and connected to 230V, the timer for "230 V" is counting.

    Once the 5 kV is started, the timer for "5 kV" is counting.

    If the time between "230 V" and "5 kV" is short, then the wrong state of the setpoint only appears for a short time (we habe seen minutes and hours).

    If there is a significant time, when the 230 V is on, and the 5 kV is off, then the difference between both timers is larger and the wrong state of the setpoint appears (we have seen days and weeks).

    Finally, each 49,7 days, the situation repeats.

    Now you know, where to look up in the controller software.

    Best wishes,

    Alexander Schnase

  • An Agilent Sales Engineer plans to be at your site on Wed 21st to upgrade the units. He has the procedure and the file for update(s).

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