Modicon Analog input scaling..

How do I scale my analog input/Output modules in Modicon Concept using LD language?

Is this done through the programming blocks...or is there something in the Configurator > I/O > rack setup where this is done?

What I need to do is setup the Engineering units for a temperature from a Temperature transmitter (4-20ma in) to equate to a J type t/c range of 0-400 Degrees F.

Also a pressure reading that will range from -20 to +20 Inches of water column. (4-20ma in). 4ma =-20 in 20ma = +20in

In Allen Bradley Contrologix this is done in the module setup.

Then the outputs are modualting there respective 4-20 ma devices.

Thanks in advance!

Scaling is done in the program not in the configuration. The configurator is only used to tell the input card what type of field signal you have.

There are quite a few different scaling blocks in Concept. Look in the Concept IEC Block Library ANA_IO for a listing.

One that I use frequently is SCALEWTOR which will take a Word (integer) input and scale it into a Real (floating point) number.

The scaling algorithm is:
VALOUT=(VALUE - IN_MIN) x (SCALEMAX-SCALEMIN)/(IN_MAX - IN_MIN) + SCALEMIN

For example:
4-20mA field device is inputed into the PLC as VALUE
Depending on the input card SCALEMAX = 32000 (or 4095) and SCALEMIN = 0
IN_MAX = 400 (or 20) and IN_MIN = 0 (or -20)
VALOUT is your scaled floating point number.

Each function block pin may be a variable, a literal, or a direct address. In LD you only need connect your logic to the EN (enable) pin and then assign the other pins.

Thanks Jim




-Jim-

One thing to watch out for: different Modicon platforms have different AI signal ranges. The logic is the same, but you can't use the identical input data ranges for Quantum and Momentum, for example.

Concept FB

Iam New in modicon CPU11303
Please can Help me with below to question :

1- whats the addressing for internal memory bits in modicon 140CPU11303 in rslogix500 we used B3:0
2- Whats the Internal memory register used to store the Analog output from SCAL FB in rslogix500 we used N7:0 for integer and F8:0 for Float

3- please can explain the Compare function Concept 2.5XL

Thank you for your help

Concept is tag based. You do not need to assign addresses to tags. Just create a tag of the type required eg BOOL, INT, REAL etc. and use that tag as required.
The only time you need to assign a tag to an address is if you need to access that tag externally eg reading from a HMI. If you do need to set an address then it follows the iec standard %M for bools, %MW for ints, reals will use 2 consecutive %MW addresses
Not sure what you mean by the compare function - there are a number of compare functions GT (greater than), GE (greater or equal), EQ, LE, LT

One thing from the earlier post I would avoid using the SCALEWTOR function. This is not supported in Unity so if in future you upgrade to Unity you will have to redo this code. Use the SCALE function (might be called SCALING) instead

Thank you

Many Thank for your help,
I try to use %M12 as internal bit , or %MW12 as internal word
but I have this message from Concept 2.5XL

Invalid selctor of register address
Error Id:19902

only accept the Register 40000n for real address and the direct input address accept 0x ,1x

I used befor %M , %MW in unity pro with no problem but Unity pro cant communicate with 140CPU11303 concept PLC
Many Thanks again for your quick help

Sorry my mistake, been a while since using Concept - to address bools use 0xxx, to address words (ints or reals) use 4xxx, a real will use 2 consecutive registers. You still only need to address tags you will be reading or writing to from external devices (HMI)