Conversion

i have a 0 to 145psi pressure transducer and at the PLC it's set 0 to 768. What would the value be at 3psi.

15.888

Thanks you much. May i ask how you did that?

768/145=5.296
3*5.296=15.888

another way, same answer

3/145=percent of span=.020689
percent of span * span=value
.020689 * 768=15.8896

Lets simplify this, any time you have 2 values in a relationship it is called a "ratio'. In this case the ratio is 768 to 145, in other words 5.296 units per 1 unit i.e. at 3psi the plc would read 3*5.296 which would equal 15.88.

Thanks alot you guys. I appriciate all the help. :site:

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

Dear sir,

I am beginner in twido plc please tell me ho to use multiplication.

No answer, but a suggestion or two.

Cspatil,
Welcome to the Forum! I see that you already tried searching the archives for an answer, so at this point I would suggest you start a new thread with your question. Please also try to provide as much detail as you can. Such as what kind of PLC, what version of software, What exactly you are trying to multiply, ect..

One thing I would advise against is asking the same question repeatedly on different threads. It kinda clogs up the works. I'm sure if you start a new thread, and provide as much detail as you can, someone here will do their best to help you.


Will.

Dear sir,


I am beginner in twido plc please tell me how to use the MOV INSTRUCTION

I love the fact that some of the old school idols of mine are still on here.