Measure 4-20mA using Genius analog input

I am todally new to this world, I am going to do a project, which need to measure the 4-20mA using GE's Genius blocks. The transduser will read the preassure of the system and give a current output in 4-20mA, I have to display the pressure using the 4-20mA. I never used any Genius module and 90-70, I need your help to understand and continue. All of your feedback are greatly appreciated.
Thanks in advance.

Genius blocks allow you to perform the scaling at the input point if you desire. You can use the Genius handheld unit to set up the scale parsameters. The data reported by the Genius block to the PLC will be a 16-bit signed integer.

For an example, if your 4-20 mA transmitter's range is 10 to 50 PSI, you could set up the Genius block to send the PLC a value of 1000 at 4 mA and a value of 5000 at 20 mA.

It's all covered in the manual GEK-904862D-2, Genius I/O Discrete and Analog Blocks.

If you don't like the idea of doing the scaling at the input block, you can let the Genius block report its default values and do the scaling in the PLC's configuration.

Thanks Steave

So, if I do the scaling, I do not have to touch the PLC program, is it correct? The transducer I have is rated from -30 to +60 psi, and the Genius (6input analog) resolution can be up to 25000 micro (4-20mA); when I do the scaling, do I have to scale 25000 is at 60psi or 20000 at 60psi, and how do I scale the (-)30?

Your help is greatly appreciated. Thanks

So, if I do the scaling, I do not have to touch the PLC program, is it correct?

I can't tell you anything about what you may or may not have to do with your ladder logic. I don't know what range of numeric values it is expecting.

The transducer I have is rated from -30 to +60 psi

Is this a differential pressure transducer? If not, what is meant by the negative pressure value?

the Genius (6input analog) resolution can be up to 25000 micro (4-20mA)

I don't understand what you're trying to say here. The Genius analog input is 12-bit resolution.

Assuming that you're looking at a differential pressure transducer with a range of -30 (Side A 30 PSI lower than Side B) to +60 (Side A 60 PSI higher than Side B) PSI, and that 4 mA corresponds to the -30 PSI differential and 20 mA corresponds ro the +60 PSI differential:

On the 4 In/2 Out blocks, the 4 - 20 mA range is actually 0 - 20 mA. That is, a signal level of 4 mA corresponds to a raw data value of 819, and a 20 mA signal corresponds to a raw data value of 4095. Without reading the data sheets I don't know if the same is true of the 6 analog input blocks. I don't know which style you have.

When you scale the signal, you enter two sets of values. The first set is the minimum and maximum raw data values. The second set is the corresponding minimum and maximum scaled values. The data reported by the block to the PLC is a signed integer, so you can use negative numbers for your scaled values.

Steve,thanks again,
I need to meassure the -ve pressure, that's why i need to use the transducer range -30inHg(-14.74psi) to 60psi, vaccume is the -ve pressure (the transducer will indicate a -ve value when its vaccume, this will happen very rarly).
I just find out that we need to write a program to the Cimplicity to calculate the pressure.
I will see how it goes. thanks for your help.

How linear is this transducer over the full range? Don't overlook the fact that you are using different units when the scaled value is negative (inches of mercury vs PSI).

Genius blocks can only handle linear scaling. If your sensor's plot of signal level vs pressure is nonlinear or shows a different slope for vacuum than for pressure, you will need to do your scaling in ladder logic.

I know that in my my app. I will have to scale the incoming signal 4-20ma to 0-100.00 pounds. I am using a CJ1W-MAD42 so how will I convert this to veiw in a NT display for weight. Or may be my scale needs to be something else but anyway I need to display a weight from this signal... for example from a 4-20ma signal 8.00ma will equal 50.00 pounds.

The allocated memory for this input starts out at 2000. How much memory will I need to leave in between, analog inputs, so they dont "overrun" I guess is what I am thinking of. Also what will the signal be coming in as (BCD, Hex, etc...) and what will I have to convert it to for the NT to display it correctly? Any hints would be appreciated.

I think my major problem is understanding data info. I probably need it spelled out for me LOL