14
There are several options in this case .
• Select a roll with a lower number of pulses per revolution . If you are using a Smart Roll with 6 pulses per revolution, switch to a 2
pulse or 1 pulse per revolution Smart Roll . The PLC will have more time between pulses and longer pulse duration . This is the preferred
method .
• Reprogram the PLC or electronics to a faster sampling rate and/or longer sampling durations .
• Change to a larger diameter roll . If you are using a 5” diameter Smart Roll without lagging, switch to a roll with ¼” of lagging to make
the Smart Roll 5 .5” diameter, or switch to a 6” diameter Smart roll with or without lagging .
CONVERTING PULSES TO BELT SPEED?
The following equation can be used to convert Smart Roll pulses to belt speed .
D = Roller Outside Diameter including lagging, in inches .
count = Number of pulses counted in the sampling time period .
Time = Sampling time period in seconds .
#pulse = Number of pulses per revolution of the Smart Roll (1, 2, or 6) .
fpm = belt speed in feet per minute .
Duration = 0.85
= 0.85
7.854 (D)
fpm (#pulse)
– 0.004
(
)
π
(D) 60
fpm (#pulse)12
– 0.004
(
)
x
1
2
fpm =
=
15.708 (count) (D)
Time (#pulse)
(
)
π
(count) (D) 60
Time (#pulse)12
(
)