PR426P Belt Weigher Transmitter with Profibus DP Interface

Features

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• DIN Rail or wall mount options
• LCD display for indication of process values, configuration, calibration and error reporting
• Flow Rate calculation in Kgs/Hour or Tonnes/Hour
• Automatic Zero Adjustment
• Both Resettable and Non-Resettable Totals
• Adjustable filtering of both weight signal and tacho signal
• Profibus DP interface allows access to all process, calibration, configuration and maintenance data

The PR426 Belt Weigher Transmitter connects with up to four strain gauge load cells fitted to a belt weigher mechanism from which it generates a calibrated weight signal. It also connects with a proximity switch or shaft encoder, from which it receives pulses in proportion to belt movement.From these two inputs and from calibration and control data held in its system memory it continually calculates the rate of flow of material over the belt and the total quantity of material transferred. Optionally, in applications where belt speed variations are insignificant, the indicator may operate from an internal tacho pulse simulator.

A Profibus DP interface is provided to allow access to all process, calibration, configuration and maintenance data from a Profibus DP master.

Configuration adjustments are performed by means of the four push-buttons in conjunction with the LCD display. Access to all calibration and configuration data is pass-number protected.

Calibration

A simple two stage calibration system is used: the Dynamic Zero is first established by running the belt empty for a preconfigured number of belt movement pulses and then the calibration is established by passing a known weight over the weigher and entering this value as the calibration total.

Dead Range Adjustment

A control parameter determines the minimum flow rate below which the unit ceases to totalise. This removes inaccuracies caused by small fluctuations in the flow rate with the belt running empty.

Auto Zero Adjustment

The internal Dynamic Zero is automatically adjusted by a small amount whenever the unit is running within the Dead Range. This compensates for build-up of material on the belt over time.

Totalising

The PR426P stores two independent material transfer totals within its non-volatile system memory. These provide the flexibility of concurrent use of a production shift total along with a periodic material usage total.

Datasheets