Rockwell Automation 1746-HSCE,D17466.5 High-Speed Counter Module - Manual (Page 130)

Publication 1746-UM006B-EN-P - August 2005
6-18 Application Examples
Rate Mode-Log Ripper Example
In the following rate example, a variable speed conveyor is being
used to feed logs into a saw blade. An encoder is connected to the
motor shaft. As the shaft turns, the encoder generates pulses and
sends them to the module. The module uses the pulses to calculate
the rate of the sawblade in Hz.
The conveyor has two speeds, fast and slow. At location #1 (refer to
speed/time chart below) logs are fed into the saw blade at the fast
speed. At location #2 the saw blade encounters an irregularity in the
log (for example, a pocket of pitch or a knot) that slows the saw
blade. At location #3 the module detects the saw blade’s reduction in
speed and reduces the conveyor feed rate. At location #4, once the
saw blade clears the irregularity and returns to its normal cutting
speed, the module increases the conveyor feed rate.
Module Input
(Saw Blade Speed)
Speed Sensor
Start
Stop
2-Speed Conveyor
Feed Motor
Fast/Slow
saw blade
Log
Fast
Time (Seconds)
Critical speed
4,000Hz
Slow
Change
conveyor
feed rate
Module Output O:1/1
(Conveyor Feed)
Off/On
Feed
SLC 5/02
Processor
High-Speed
Counter Module
Output Module
Input Module
I:2/0
O:3/0
O:1/0
I:2/2
I:2/1 I:2/3
O:1/1
Control Panel
Feed
Motor Saw
Motor
Slow
Feed
Indicator
1
2
3
4