Rockwell Automation 1746-NR4 SLC RTD/Resistance Input Module User Manual - Manual (Page 80)

Publication 1746-UM008B-EN-P - December 2006
80 Channel Configuration, Data, and Status
User-set Scaling Using Proportional Counts Data Format
Configuration Words For User-set Scaling (Words 4…7)
In the Limit Scale Words example, it shows the address of the user-set
limit scale words used to define the lower value and the upper value
of the user-set scale words. You can use these words when:
• bits 13 and 14 (scaling select) of the channel configuration word
are 01 (Limit Scale 0) and proportional counts mode is selected.
• bits 13 and 14 (scaling select) of the channel configuration word
are 10 (Limit Scale 1) and proportional counts mode is selected.
These scaling words are global for the module. They are not exclusive
to a particular channel. Be sure the scaling limit range is used on only
compatible channels. Use range 0 or range 1 to apply the appropriate
lower limit word and the upper limit word to any single channel or
channels which are configured for user-set scaling for proportional
counts.
Any time a range is selected, and an invalid combination of scaling
limits is in that range, a configuration error occurs. For example, if
both scaling limits are 0, or if the lower range value is greater than or
equal to the upper range value, a configuration error occurs.
Limit Scale Words
Lower scale limit set for 3
Selected Configuration Words 4 & 5 for Scaling
CH 3 Configuration W ord
0 15
O:e.3
0 15
0 15
0 15
0 15
O:e.4
O:e.5
O:e.6
O:e.7
Defines lower scale limit for range 1
Defines upper scale limit for range 1
0 1 1 1
1 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0
0 1 0 0 1 1 0 0 0 0 0 0 0 0 0 0
1 1 0 0 0 0 0 1 0 1 0 0
Selected 1000 Ω Pot
Selected Proportional Counts Data Format
Upper scale limit set for 50
Range 0
Defines lower scale limit for range 0
0 15
0 15
0 15
0 15
O:e.4
O:e.5
O:e.6
O:e.7
Defines upper scale limit for range 0
Defines lower scale limit for range 1
Defines upper scale limit for range 1
Range 0
Range 1