How to provide an analog output based on data calcs?

hillp · Post by **hillp** » Wed Feb 11, 2004 11:15 pm

I'm using a pressure transmitter and ADC16 with Windows 95 to collect data on liquid level rising in a tube in a lab. After the fact I go back and use Excel to calculate the flowrate of liquid into the tube from the increase in level per time.

What hardware and software would I need to do this calculation online (while measuring it) and then output an analog signal (preferably 4-20 mA) to feed into a separate process controller? I haven't been able to find a standalone flow transmitter for this very low flow (5 mL/minute) of a corrosive liquid (it would dissolve stainless steel in a matter of hours). I assume I'd have to write some software to do this, but am not experienced in this area, so the simpler, the better.

Thanks,
Pete.

markspencer · Post by **markspencer** » Thu Feb 12, 2004 12:30 pm

Hi,

To do what you want you could use Excel to get the raw data then change this in to the voltages that you get in Picolog, after that you would need to provide your own scaling. The simpilest solution would be to use the driver functions and the example already provided with the installation software.

However, it would also be possible to use the driver with C/C++, delphi, and VB. Alternatively, you could write your own communication protocol, however form what you have said I would not advise this approach.

Best regards,