Decimal display

Can someone please help me setup a analog input from S7 plc to view as decimal value with 3 decimal places on wonderware scada.
eg. -1.123

Thanx

I would assume that wonderware has the ability to display real numbers. You should also be able to set the number of decimal places in wonderware.

Just pass it over to the SCADA as a real.

Paul

P.S I have no experience at all with wonderware only with S7's

Paul I think the problem may go deeper than he stated. Krish have you managed to scale the incoming value to the values you need to display?

If I am not mistaken the analog input goes into an AIW, this will probably needed to be converted into at least a 5 digit value of the range you need then divide by 1000 and put the result in a double word address...VERY simple example: lets say its 12 bit resolution (4096) and you need to read 0-10. Multiply 4096 by 2.441 then divide by 1000.

I believe the end result will need to be a double word address. You should be able to create a numeric display in Wonderware with the number of digits needed....ie you are display 0-10 volts at 1/1000s resolution you will need a 5 digit numeric display. This can usually display in different formats like 01.123 or just 1.123...most allow you to fill with zero...ie 01.220 instead of 1.22, that choice is yours but usually it eliminates read errors. As PLucas stated assign this numeric display to read from a REAL (floating point) address.

I hope I said this right.

Let me try to explain better.
I have a vacuum switch with 4-20mA out with -1 bar being 4mA and +1 bar being 20mA. This is wired into a siemens analog input module with PIW(word) as input.
I want the scada to indicate the actual vacuum value as indicated on the local gauge.
Its the plc conversion that I do not fully understand as yet.

Krish,

Have a look at FC105 "SCALE". This block will give you a 'scaled' output in REAL format, ready to go straight into your SCADA package.

FC105 can be found in the "Standard Library" -> "TI-S7 Conversion Blocks"

Highlight the block, then press the F1 key for the help file.

I haven't used this block, but you might have to 'play' with the LO_LIM setting to get it to scale your value correctly, as I would assume that the block would take zero (0mA) as the low limit.

Paul

I do not use Wonderware but use Citect regularly. If you do not wish to use the numbers in the PLC, you should be able to scale it in the SCADA quite easily.

Eg: Raw value 0000 to 4000
Engineered value -1000 to +1000
Set up the decimal point in the actual number display. Select the name to display with the number display (bar)(Citect anyway).