Red Lion LEGEND - Manual (Page 63)

APPENDIX “A” - SCALING FOR COUNT AND TOTAL INDICATION
SCALING FOR COUNT INDICATION
The Legend Plus is factory set to provide 1 count on the display for each pulse that
is input to the unit. In many applications, there is not a one to one correspondence
between input pulses and display units. In these applications it is necessary for the
Legend Plus to scale or multiply the input pulses by a scaling factor to achieve the
proper display units desired (feet, meters, gallons, etc.). The Count Scale Factor, the
Count Scale Multiplier, and the Number of Count Edges are used in scaling the input
pulses to the desired reading. The number of count edges is determined in the
Program Counter Module. For example, the number of edges for the CNT+DIRX1
mode is one and the QUAD X4 mode is four. All three are factored together to
provide the Scaling necessary for the Process display. The Count Scale Factor and
Scale Multiplier are programmed in the Program Scaling section.
The first step in scaling requires the Number of Pulses per Display Units to be
obtained. This may require a small amount of deductive reasoning.
Example: A 48-tooth gear is mounted to a 2 ft circumference feed roll in a paper
processing plant. It is desired to display the footage of paper processed per
day. In this example, the display units are in feet. A sensor sensing the gear
teeth provides 48 pulses for each revolution of the feed roll. Each revolution
equates to a linear distance of 2 feet. The number of Display Units desired is 2.
The Number of Pulses per Display Units is 48. When the number of Display
Units and the Number of Pulses have been obtained, the Total Scaling can be
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TROUBLESHOOTING GUIDE (Cont’d)
PROBLEMS POSSIBLE CAUSE REMEDIES
NO RATE INDICATION 1. No signal at Input A. 1. Check sensor connections.
a. Verify power to sensor.
2. Type of input signal selected incorrectly. 2. Check DIP switch setting on side of unit.
3. Rate Scale factor and/or Rate Scale Multiplier 3. Check scale factor value and scale multiplier
too small. values.
INCORRECT RATE READING 1. Input signal type incorrectly selected. 1. Check DIP switches. Set HI/LO FRQ. switch to
LO for a count speed of less than 50 Hz.
2. Inputs improperly connected. 2. Check sensor input connections.
3. Electrical noise interference. 3. Check power source for noise.
a. Check signal wire routing.
4. Scale factor incorrect. 4. Verify scale factor value.
5. Rate input signal too high of a frequency. 5. Verify input signal.
RATE DISPLAY FLASHING 1. Rate Scale Factor, Multiplier and/or Conversion 1. Check values.
OVERFLOW Factor values too large.
2. Minimum update time set too high for input rate. See
Note in “Programming Rate” Section.