high voltage power supply serial communication

[Eric-APU]

Hi All,

      I have multiple power supplies (Bertan 230's mainly, but others as well), which I would like to control using RS232 communication. However, the documentation provided with the supplies gives a list of pin assignments, instead of commands which the device can interpret. Below is a list of the assigments for a 230 model. I would like to be able to actively control the voltages, read the voltage and current, and toggle the supply on or off. I have very limited experience with serial communication, but have good experience in instrument control through a DAQmx AIO board. Attached is the pdf of the PS's manual. Thank you in advance for your help,

<>< Eric

 Pin 1: Voltage Monitor (0-5 VDC = 0 to 100% rated Voltage)

 Pin 2: N/C

 Pin 3: Enable (TTL "0" disables HV, TTL "1" or open enables HV)

 Pin 4: +5Vdc Reference (+5.0 Vdc @10 mA, maximum)

 Pin 5: Current Monitor (0 to 5 VDC = 0-100% rated current)

 Pin 6: Voltage Program Input (0 to 5 VDC = 0-100% rated Voltage)

 Pin 7: Analog Ground

 Pin 8: Digital Ground

 Pin 9: Polarity Indicator (Open Collector, 30 V @ 25 mA, positivie = ON) 

[AnalogKid2DigitalMan]

Eric:

According to the documentation you posted, there is no serial communications port. So use a DAQ card to control/monitor the supply which you said you were experienced in.

-AK2DM

[Dennis_Knutson]

That's not RS-232 at all. They are using DB connector for analog/digital control. You would need a DAQ board to provide the inputs and outputs.

Your other supplies may in fact have RS-232 control. You would have to look at the actual specs and manual and not infer anything from some physical connector that might be present.

[Eric-APU]

Your above suggestions worked very well, thank you very much. However, I have now run into another problem. In trying to control multiple supplies, I get an error saying a resource is in use. Does creating an analog input use the counter/timers on the board? I need to simply take a voltage reading on a line every so often without using any counter/timers. Is this possible? Attached is the VI I am using.

[Dennis_Knutson]

You indicate that this is a subVI but it can't possibly work as a subVI. The only way that it will stop is if you get an error.

In any case, I run this and don't get an error. You should get rid of the sequence structure. Not necessary at all. The resource reserved error is either the DAQmx Write or the DAQmx Read. If you are doing either in the main VI, that would cause the error because you can only have one task running for a specific hardware resource. It's also silly to start and stop three separate tasks for the analog in. Use a single task with multiple channels.

[Eric-APU]

I think I misrepresented what I was trying to do. I did not mean I would use it as a subVI, only that I would use this program in a larger program I have already written. This was a test to make sure this would work. The reason the sequence structure is in place is when I got rid of it, I got the error. What I am trying to do is this: I have an overall program running a pulsing sequence and analog read to a waveform. This is already programmed and working. What I want to add to it is the ability to control and monitor multiple power supplies, which operate through analog channels (an out channel from 0-5 volts, and 2 in channels from 0 to 5 volts), performed twice. All of this needs to operate simultaneously using an ADC board (16 in channels, 2 out, plus 2 timers. I am at home right now and cant remember the part number for the DAQmx board I have). Is this possible, and if so, how can it be done? Thanks,

<>< Eric

[Dennis_Knutson]

The reason you got the error when you removed the sequence structure is that you were running the DAQmx tasks in parallel and you cannot do that. As I said, you cannot have more than 1 task running with a single hardware resource. That single resource is the DAQmx Write. You either have a single task that you specify all channels at the same time or you sequentially open and close each task.

p.s. You still do not need the sequence structure. If you do control one at a time, get rid of the error popup and just wire the error in/error in through all of the tasks.

[Eric-APU]

Thanks for your advice. I will try this and post the result. I do not have experience wiring multiple DAQ write tasks, I got these out of the examples, but I will see what can be done. Thank you for your help,

<>< Eric