analog conversion scales

I have a Keyence CCD digital micrometer (LS-7000). The application is to give a diameter of a part. The controller gives out the diameter of the part and also gives an analog output of +-10v. The PLC used is a KOYO 240 cpu with an analog input card. What I need is to convert this analog signal to give me the diameter of the part. I get a clean analog voltage but don't know how to convert (scaled data) it to mm in the PLC program. The required scale is +- 10v to +- 10 microns.
Any help in conversion of this nature will help. The exact program method of this equipment is not required. Need help fast.
Thank you!

Download the DL205 Analog I/O Modules manual HERE. They explain how to scale your data VERY well in there.

Basically though, you just multiply by 1000 to convert micons to mm...

beerchug

-Eric

For any unit conversion on any PLC you can use four function math with the following, which asumes integer math:

DataOffset = Data in input register at 4 mA (or zero analog signal of whatever range - for example 0 VDC on a 0-10 VDC transmitter)

DataSPan = Data at 20 mA - Data @ 4 mA

FACTOR = arbitrary factor (multiple of 10) needed to get proper resolution and accuracy

EU = Engineering Units x FACTOR

EUOffset = Engineering Units @ 4 mA x FACTOR

EUSpan = (Engineering Units @ 20 mA - Engineering
Units @ 4 mA) x FACTOR

DATA = Actual data reading in input register

EU = ((EUSpan x (DATA - DataOffset))/DataSpan) + EUOffset

ProcessValue = EU / FACTOR

For Example, 0-60 psig from 4-20 mA with resolution of 0.1 psig:

FACTOR = 10
Data @ 4 mA = 6240
Data @ 20 mA = 31208
DataOffset = 6240
DataSpan = 31208 - 6240 = 24968
EUOffset = 0 x 10 = 0
EUSpan = (60 - 0) x 10 = 600

DATA = 18975

EU = ((600 x (18975 - 6240)) / 24968) + 0 = 306

Process Value = 306 / 10 = 30.6 psig

Thank you!!!!
I was able to get things working yesterday. It was not the plc program giving me the problem. It was the lack of understanding the programming of the micrometer analog signal.

Thanks again.