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7.4 - Performing a ramped output

We've talked a little about setting an output from a screen control in section 4.6, but this requires user input. We also talked about setting an output based on an input in section 7.1. In this section we learned that you can easily set an output channel by simply assigning a value to it. So, to set a DAC channel named ValvePosition to 3 volts (assuming no Conversion exists on the channel), we would simply do:

ValvePosition = 3

You can also apply conversions to outputs like we did with inputs in section 4.3, however, the conversions work in reverse. For inputs, the conversion takes the raw voltage (counts or other units) from the LabJack and converts it into engineering units like temperature or pressure. For outputs, the conversion takes the engineering units and converts into voltage. So, for if we had a proportional valve that takes a 0 to 5V signal and we want to be able to specify the percentage open, where 0% = 0V and 100% = 5V, the conversion would be:

Value / 20

Then, to open the valve to 60% we could just do:

ValvePosition = 60

and 3 volts would be outputted from the DAC of the LabJack.