Harris Instrument LCPU - Loop Control Processing Unit


The SCAN-A-LINE™ Model LCPU –Loop Control Processing Unit – from Harris Instrument Corporation is specifically designed for controlling accumulator loop systems and is built for operation in loop accumulators up to forty feet [12.2m] long. When the bottom of the loop is located at one half the distance from the emitter to the receiver, the control range of the loop controller will be approximately 50% of the length of the emitter. With a Scan-A-Line 10XHD-40 (40 inch emitter) the control range will be approximately +/- 10 inches (+/-254cm). Smaller 10XHD-Series emitters will have proportionally less control range. The LCPU features both unipolar (0 to +10VDC) and bipolar (-10 to +10VDC) analog outputs for interface with other equipment. When 50% of the emitter is blocked by the bottom of the loop, the analog output will be at mid range. The Unipolar output will be +5Volts. and the Bi-Polar output will be a zero Volts. These analogs can be used to modulate the take-away speed at the exit of the accumulator to prevent overfill..

The Model LCPU monitors sensor scan rate and system power supplies to alert the operator to a sensor system malfunction before an incorrect control signal causes an accumulator overfill. The FAIL-SAFE circuitry contains normally-open (NO) and normally-closed (NC) relay contacts. Excess error limits are also available as NO relay contacts closures on the bargraph display.



  • A Vertical Bargraph Display mounted on the front panel (as standard) displays the loop position, FAIL-SAFE status and positive or negative excess error limits. Two normally-open (NO) relay contacts are provided for excess error limits.
  • Compatible with all 10X-HD series sensors
  • Two FAIL-SAFE Relay Outputs: One Normally-Open (NO) and One Normally-Closed (NC).
  • Limits Relay Outputs: NO relay contacts on the Bargraph display will close when the High or Low Limits are exceeded. The set points can be adjusted with the Bargraph sensitivity control.
  • Position Analog Outputs: Bipolar (±10VDC) & Unipolar (0-10VDC).
  • 105VAC to 120VAC (220VAC available) Linear Power Supply (±12VDC regulated for sensor and 5VDC regulated for logic circuits) and signal routing for one Model 10XAHD Sensor.



  • 220 Volt AC Operation (220 Option): No-charge option for 220VAC installation.
  • Remote Display (BGA50/V Option): Remote mounting kit for the vertical bargraph display. (Includes sample cable and mounting instructions.)
  • Line Receiver Option: To drive Emitter to Processor cables longer than 50 linear feet.