TABLE OF CONTENTS Pages Symposium 1 - the National Sea ...

feeder control algorithms on a PC separately from the development of the detection unit
and possibly integrate them on a later model.
The transducer orientation was also changed for this second unit. The transducer was
mounted to the top of a standpipe to send the signal down into the standpipe rather than
across the cross section. This change resulted in better detection because it moves the
detection volume out of the unstable near field and also facilitates installation, removal and
cleaning while the production system is operating.
Table 1. Comparison of Feed Detectors.
Feature Generation 1 Generation 2 Generation 3
(Commercial)
Parameter
Dip Switches Dip Switches Software
Configuration
Selectable
Networkeable No As slave to PC or Included 2-wire
PLC
RS-485
Operator Detection Single LED Multiple LED’s LCD or PC Display
Feedback
Detection Primarily based
Signal Gain
2
Primarily based on
Signal Gain
Signal Gain and
Proprietary
Algorithms
Integrated Feed
Control
Yes No Yes
Feed Control Interval No Time of Day or
Interval
Transducer Mount Perpendicular to
Flow
Parallel to Flow Parallel to Flow
Configuring
Manual Manual Semi-Automatic or
Detection Settings
Manual
The current unit has returned towards the integrated approach of the first prototype by
combining waste feed detection and feeder control into one box. The manufacturer has
added both circuitry and software algorithms to improve particle detection. In addition to
an interval timer, the unit has an event timer that can be programmed for feeding at
specific times during the day. Proprietary algorithms have been added by the
manufacturer to enhance pellet detection and decrease false counts. Significantly, the dip
switches have been replaced by software routines so that the user can change values using
an integrated LCD display and keypad without opening the enclosure. In addition, the
unit has 2-wire RS-485 communications for remote configuration and access to more
advanced features on a PC. The RS-485 network also allows multiple units to be accessed
on a single PC. Table 1 lists a brief comparison of the three units.
Performance of Generation 3
In a 1500 L flow-through tank containing 120 kg rainbow trout being fed a 3/16” Zeigler
Trout diet, the UltraEye unit has shown the ability to detect the differences in feed