3
Introduction
The CS-5100 is a series of ultrasonic sensors integrated with a microprocessor based control card. All
of the series of controls use the same control electronics. The sensing head varies from product to
product. The base CS-5100 is a single transducer ultrasonic sensing system. The CS-5140 has a four
transducer sensing module where each sensor is polled sequentially. It is used in situations where the
target stock moves around and the array provides a larger sensing area. The CS-5103 is a three
transducer system. Two extra transducers are used exclusively to increase the sound pressure of the
acoustic burst, thereby increasing the likelihood of an echo return from very narrow materials. The
CS-5100L is a laser sensor version of the standard CS-5100.
All of these variations of the control have been specifically designed to monitor material hung in a
slack loop. Slack loop control is used for the feed and/or rewind of products manufactured in a
continuous, linear manner. The diagram below is more instructive of the control's purpose. Typically,
the CS-5100's sensor(s) is placed over a draped loop of slack material. The position of the loop valley
is sensed and is used to govern the speed of a follower device (in the diagram, it's a powered winder).
These controls may be programmed to control either upstream or downstream process followers.
Typical of upstream devices would be decoilers, straightener/flateners, dereelers. Typical downstream
devices would be winders, cut-to length machinery.
The ultrasonic transduction is fairly straightforward. A burst of acoustic energy is broadcast toward the
target (the loop valley). Milliseconds later, the transducer is switched to receive mode to await the
echo return. The time between transmit and receive is measured. The speed of sound in air is
reasonably constant so the position of the target is accurately calculated by the system's processor.
The system works best when the target viewed is perpendicular to the beam axis. Some angular
variation is tolerated (about +/- 5 angular degrees), but when the angle is too severe, the echo return
misses the receiver entirely. In this case, the system will register a far loop even if the target is
physically in the control range. Most loops have either a parabolic or catenary curvature which aids in
bouncing the echo back to the receiver, much like a radar dish does.
When the system is set-up, a control range is defined. Near and far set points define it. Within the
control range, a signal (both 0-10VDC and 4-20mA are available) varies from either low to high or
high to low.
