Created Date: January 17,2009

Created by: KPrice

twitte, A couple of questions come to mind,

Did you setup the data format for binary or BCD?

You may need to use double-word instructions with BCD format.

The DIV instruction is a single-word BCD instruction.

Is your temperature value negative?

Could you be over-writing the V-memory location that holds your calculated temperature?

Have you tried the SHFR K4 instruction to remove first digit?

Your HMI may have a scaling feature available with your numeric display object.

Do any of these ideas this help?

Created Date: January 19,2009

Created by: twitte

Thanks for the suggestions.

Right now I have it set up for binary numbers, I will try changing it to BCD. I will also try removing the first digit with the command you listed. When I tried dividing before I was using a new v memory location. All my reading are unipolar. I realized you can scale on the HMI for some situations, but not for all situations, like the graph feature on the CMORE.

Thank You

Created Date: January 21,2009

Created by: JimHoward

twitte,

Following is my method of working with the F2-04RTD module. Display the result V2010 on your HMI as real, as it will show both positive and negative temperatures.

PLC 260

// Rung 1

// Address 0

#BEGIN COMMENT

"First, the raw RTD data is 15 bit Binary, with a " "sign bit " ", in the format " "magnitude plus "

"sign " ". The sign bit is masked off with the ANDD function, before the Binary data word is "

"converted to Real. As the data is in tenths of degrees, divide by 10 for whole degrees. "

#END

STR SP1

LD V2000

ANDD K7fff

BTOR

DIVR R10

// Rung 2

// Address 8

#BEGIN COMMENT

"Second, if the sign bit is ON (which indicates a temperature below zero), multiply the "

"above real temperature data by -1 to make the real temperature data negative. "

#END

STR B2000.15

MULR R-1

// Rung 3

// Address 13

#BEGIN COMMENT

"Third, filter and smooth the real temperature data, which helps reject any noise induced "

"into the field wiring. The filter simply takes the difference between the previous filtered "

"data (scratchpad) and the current data, and multiplies it (MULR) by a " "filter factor " " (note, "

"a smaller number increases the filtering) and adds/subtracts that to/from the previous "

"filtered data. "

#END

STR SP1

SUBR V2020

MULR R0.2

ADDR V2020

OUTD V2020

OUTD V2010

// Rung 4

// Address 21

STRN SP0

AND X50

OUT C1000

// Rung 5

// Address 24

NOP

#BEGIN ELEMENT_DOC

"X50 ", "XMTR_RTD-1 ", " ", "Broken XMTR, RTD Input - Base0/Slot2/Ch1 "

"C1000 ", "XMTRRTD1 ", " ", "Broken XMTR, RTD Input - Base0/Slot2/Ch1 "

"V2000 ", "_RTD-1 ", " ", "Raw RTD Input - Base0/Slot2/Ch1 (Binary) "

"V2010 ", "RTD1 ", " ", "Air Inlet Temperature (Filtered, Real) "

"V2020 ", "__RTD-1 ", " ", "Scratchpad RTD Input - Base0/Slot2/Ch1 (Real) "

"B2000.15 ", "Sign_RTD-1 ", " ", "Sign Bit, Raw RTD Input - Base0/Slot2/Ch1 "

#END

Created Date: January 16,2009

Created by: twitte

I have a fairly basic question which I can't solve. How can I divide my RTD card reading (F2-04RTD) by 10 so I can properly display it on my HMI. I tried using LD (vmemory of reading) DIV (k10) and OUT (new v memory), but this did not work. Any help would be great.

Thank You

Tyson