adccommunitymod (AutomationDirect) asked a question.
Created Date: January 24,2005
Created By: Justin27
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I have a 250-1 in a local rack. I set up an analog input module for binary and 4 channel input. LD K8400 OUT V7663 LDA O4500 OUT V7673 I then entered this rung LD V4500 BTOR DIVR R 4.095 RTOB OUT V5000 I wanted to scale my analog input to 0-1000 representing 0-100%. When I vary the input from 0-10 VDC the data in V5000 will not track the full range of the data in V2000. I found I had to add a MULR R1 between the BTOR and the DIVR R4.095 to get V5000 to track V2000. Does this make sense? I don’t understand the MULR R1 Justin
Created Date: January 24,2005
Created by: Justin27
I have a 250-1 in a local rack.
I set up an analog input module for binary and 4 channel input.
LD K8400
OUT V7663
LDA O4500
OUT V7673
I then entered this rung
LD V4500
BTOR
DIVR R 4.095
RTOB
OUT V5000
I wanted to scale my analog input to 0-1000 representing 0-100%.
When I vary the input from 0-10 VDC the data in V5000 will not track the full range of the data in V2000.
I found I had to add a MULR R1 between the BTOR and the DIVR R4.095 to get V5000 to track V2000.
Does this make sense?
I don't understand the MULR R1
Justin
Created Date: January 24,2005
Created by: ericn
Why bother using real numbers? The example in the analog manual should work just fine. Assuming your 0-4095 value is in V4500, then:
LD V4500
MUL K1000
DIV 4096
OUT V5000
-Eric
Created Date: January 24,2005
Created by: marksji
Originally posted by Justin27:
Does this make sense?
I don't understand the MULR R1
Not really, but I agree with Eric, don't bother with real numbers, your not gaining anything using them.
Created Date: January 25,2005
Created by: JimHoward
Justin,
Based on your description, I'm assuming you are using an F2-04AD-2 (4 channel, analog voltage input module, capable of 0-10 VDC inputs).
When the raw data is brought in (Ch.1 - V4500, Ch.2 - V4501, Ch.3 - V4502, Ch.4 - V4503) as Binary; there is "extra baggage " in the form of the module diagnostic bit, and the sign/failure bit; that should be stripped off the raw data before you perform any calculations. Here's how I'd do it:
PLC 250(-1)
// Rung 1
// Address 0
STR SP1
LD V4500
ANDD Kfff
BCD
MUL K1000
DIV K4095
OUT V5000
// Rung 2
// Address 8
STRN SP0
AND B4500.15
OUT C1000
// Rung 3
// Address 12
STRN SP0
AND B4500.14
OUT C1001
// Rung 4
// Address 16
END
// Rung 5
// Address 17
NOP
#BEGIN ELEMENT_DOC
"C1000 ", " ", " ", "Sign Bit or Channel Failure, Analog Input - Slot 3, Ch.1 "
"C1001 ", " ", " ", "Electrical Noise, Analog Input - Slot 3, Ch.1 "
"V4500 ", " ", " ", "Raw Analog Input - Slot 3, Ch.1 (Binary) "
"V5000 ", " ", " ", "Scaled Analog Input - Slot 3, Ch.1 (BCD), 0 - 100.0% "
"B4500.14 ", " ", " ", "Electrical Noise, Analog Input - Slot 3, Ch.1 "
"B4500.15 ", " ", " ", "Sign Bit or Channel Failure, Analog Input - Slot 3, Ch.1 "
#END
The ANDD lets only the lower 12 bits pass through to the "scaling math ". The binary data must be converted to BCD before you use the MULT and DIV. The output of this "scaling math " is a BCD number.
Note, that in my documentation description I include the data type (Binary)(BCD), so I don't mix-up the data types.
In your example, the "sign bit/channel failure bit " should never come on, as you have a 0-10 VDC (unipolar) voltage signal. Also, the "electrical noise bit " should never come on. The NOT SP0 simply disables the alarm bits (C1000 & C1001) for one scan, as they are not reliable for the 1st scan.
Good luck with your project.
Jim