CJ1W-MAD42 Calibration

[denise01 3]

Hello, I use a CJ1W-MAD42 to convert a 16000 Volt Power Suppy reading and transfer to a NS 10 Screen. The output from the Power Supply voltage monitor is 1.6 volts but I have to massage the off set value through the NS Screen to get a accurate reading that matches a High Voltage Meter that I have. I looked at calibration ie Off Set and Gain. Am I right in thinking that the Input reading in my CJ1M is a signed digital reading. How can I programme so the reading on my NS is a accurate portrayal of the voltage on the monitor. In the manual it talks about calibrating using the bits of the Input 1 do these bits have to be permanantly turned on. Hope I am making sense

[Mendon Systems 22]

If you use the MAD42 internal calibration you must turn the calibration bits off when the procedure is completed. I have always found it easier to use whatever you get from the analog inputs and set up the gain and offset parameters in D registers that are adjustable from the touchscreen. You can then use a math calculation calculation to get the exact value you want. (Value = Input * Gain + Offset) For the case you have I would convert the input value to floating point and also use floating point for the gain and offset. If you have the MAD42 set up for 0-5 volts with a resoulution of 8000 your full scale input value (1.6 volts) would be 2560. To convert that to 16,000 you would need a gain setting of 6.25 and an offset value of zero. Once you get your math calculation working with fixed input values of zero and 1.6 volts you can adjust the gain and offset as required to get an accurate reading on the display.

[denise01 3]

Many Thanks, Voltage reading looks great now. I also display the current reading. This is also taken from a monitor on the power supply. It converts a mV reading to mA at a step down og 1000.1. I tried the floating point but didnt seem as good. I am reading 3.7mV at the Power Supply and do a very small current