Rockwell Automation 1771-OFE/B Analog Output Module User Manual - Manual (Page 34)

3-8
Publication 1771Ć6.5.30 - November 1998
If you do not wish to scale a particular channel, set the scaling values
as shown below.
If your range is:
Set Maximum
Scaling Value to:
Set Minimum
Scaling Value to:
4Ć20mA
1Ć5V 4095 0000
0Ć10V
+10 to Ć10V 4095 Ć4095 1
1 This also requires you to set the appropriate sign bit in the configuration word for the minimum
scaling value.
For example, suppose you choose the 1 to 5 volt range and BCD
data format for your module. You have a thermocouple input that
reports a temperature between 100
o C and 900 o C back to your
processor. You would like this input temperature scale to correspond
to an output meter scale.
You would enter the following minimum and maximum scaling
values into Words 6 and 7 of the write block:
Meter Scale Value Scaled Value Output Voltage
Unscaled
Value (BCD)
Meterscale 100% 900 o C 5.0V 4095
700 o C 4.0V 3072
Example:
Word 6 = 0100
Word 7 = 0900
500 o C 3.0V 2048
Example:
Meterscale 31%
Meterscale 25%
350 o C
300 o C
2.25V
2.0V
1280
1024
Meterscale 0% 100 o C 1.0V 0
If the processor sends a data value to the module that corresponds to
350
o C, the value is scaled to the 100 o C to 900 o C range and the
corresponding output voltage for that channel is 2.25 volts, which
would position the scale accordingly at 31% of full scale.