Position: This weigh controller is designed for Bin Scales, Belt Weighing, Weigh Feeding or Loss in Weight applications the weigh controller Superintendent is the basis of a precision weighing system which can include local control and interfacing rivalling that of a PLC. The controller Superintendent has 5 major subsystems which can be implemented individually or in combinations to build sophisticated weighing applications. The subsystems available are;
Belt Scale, Bin Scale or second "Dual" Belt Scale Controller , Loss In Weight System, PIDD Flow Controller, On Stream Calibration
IPC-14 weigh controller Superintendent Operator Interface
IPC-14 Superintendent General Features The weigh controller is a highly accurate and stable weighing device with two high precision 24bit Sigma-Delta load cell inputs which are resistant to electrical noise and allow distances of up to 1000 cable metres between the load cells and the weigh controller unit. The IPC-14 powers up to 6 load cells in parallel and works with load cells of all sensitivities.
For weighing on belts and in screws, a tachometer input is provided. The input for the tachometer sensor is optically isolated and is universal 2 wire, 3 wire or 4 wire, NPN or PNP at frequencies from 1 Hz to 100 Hz.
Outputs include traditional 4-20mA flow rate as well as a totaliser pulse and alarms. In addition full read write of output and set-up data is available via the standard Modbus/RS485 interface.
A local 4 line x 40 Character LCD weight display with bright LED backlight provided a great deal of local output and status information in a highly readable format in a wide range of light conditions. The local 16 key, keypad allows full computer terminal style data entry and has audible as well as tactile feedback.
The weighing controller uses advanced electronics which retain set-up data in memory indefinitely without the need for battery backup. A battery backed real time clock is available which teamed with the extensive memory capacity allows audit trail and trend data to be stored over long time periods.
so that a noisy Set Point will not be a source of loop instability.
With the wide array of fully isolated input/output modules which can be plugged directly onto the PCB many configurations are possible. It is possible to include a Set Point input, Flow Rate (PV) output and Control Output and still have one 4-20mA I/O channel free.
Up to 5 fully optically isolated digital I/O are available to interface with the conveyor and can be the basis of a complete remote control interface via the RS485/Modbus protocol.
Bin Scale and Loss In Weight
The 24bit Sigma/Delta weight input subsystem with data reporting rates from 10 Hz to 1000Hz is ideal for Loss In Weight flow indication and control. Combined with our real time statistical "Least Sum of Squares" method of determining a new flow rate number every second, the weigh controller is a powerful system for calculating Loss In Weight flows.
The Least Sum of Squares (LSS) line fit for flow rate derivation uses the equivalent of quadruple precision arithmetic to provide an errorless (without rounding or precision error) determination of flow rate. The system utilises a data buffer which stores around 5,000 weight and time readings. At 10Hz, this is a time period around 8 minutes. This long period would be used for particularly small or noisy flow rates.
Combined with the weigh controller functions of the weigh controller it is possible to configure a system which has three (4-20mA) analog outputs, Bin Weight, Flow Rate and weigh controller Output and one Set Point input in addition to various status inputs and/or outputs.
Belt Weighing Applications
The weigh controller is the basis of a full featured belt weighing system. The Controller meets the highest OIML Class 0.5 and NTEP requirements for trade purpose.
The Controller includes many automatic features to make it easy to obtain precision results, such as auto zero, auto span and automatic zero tracking.
The Controller has been developed explicitly as a belt batching system and is rich with belt weighing specific features born out of CST's long term specialisation in precision belt batching controller.
Dual mode allows two simultaneous belt scales in process weighing control applications.
Weighing Applications On Stream Calibration
It is possible to configure the system to provide "On Stream Calibration" to a weigh feeder attached to a weigh bin.
In this case all but the LIW sub-system is enabled, that of Bin Scale, Belt Scale, weigh controller and On Stream Calibration. The OSC will take place continuously, each time the bin is refilled and is fully remote controlled via the Modbus serial interface.
The weigh system checks the actual Weigh Feeder totaliser advance against a captured change in bin weight and uses the bin weight as a calibration reference. OSC can adjust the Weigh Feeder Zero and/or Span under operator supervision. On Stream Calibration is ideal for non-stop systems.
Applications in Weigh Feeder
The Controller is well provided with the additional input - output capacity necessary to be an effective weigh feeder flow rate weigh controller. The controller includes an advanced PIDD (Proportional - Integral - Differential - Distance) weigh controller algorithm with two stage digital filtering enabling it to competently control even the most noisy flows of material. The incoming Set Point signal is digitally filtered
Superintendent Series weigh controller Control Systems Technology Pty Ltd, Sydney, Australia
