Elegant economic operator-friendly batch weighing

Familiarity with the extensive capabilities of the PC to provide comprehensive information exchange between man and machine, has led to a rapid rise in expectations from industrial weighing sensors

Familiarity with the extensive capabilities of the PC to provide comprehensive information exchange between man and machine, has led to a rapid rise in expectations from industrial measurement and control instrumentation.

In major plant installations full SCADA type computer-based instrumentation fulfils this demand, but in smaller or more dedicated installations cost has often been a barrier to the provision of better man to machine interfaces.

In the field of process weighing, it is no longer considered good enough to inform the operator about the measurement values and status of the process through coloured lights or coded displays.

The operator is asking, and rightly so: "If my PC can do it at a reasonable cost then why can't the weighing instrumentation in my factory".

New generations of weighing instruments and the availability of standard fieldbus digital communications techniques have resulted in a convergence of influences, which offer an elegant solution.

The TAD 3 new generation weight controller, a highly precise instrument, allows the weight signals coming from load cells supporting a process vessel to be resolved internally to nearly 14 million divisions.

This basic building block also has some excellent batch weighing software and the capability to communicate with other machines via its two digital fieldbus outputs.

The limitations placed on such a device by physical size as well as internal memory do mean that the operator interface that can be built into the envelope of the instrument, whilst fine in many applications, is necessarily limited.

Partnering this unit with one of a series of external display units that also have standard fieldbus interfaces provides a very economic operator interface.

Depending on the size and model of display chosen information can be presented in graphical as well as alphanumeric format.

The displays are simply designed to suit the needs of the process by a PC-based configuration program.

This means the associated engineering costs are kept to a minimum and the user is also granted the flexibility to cope with those last minute occurrences that seem to be a feature of most control systems.

The system is completed by the provision of I/O through external relay or solid state modules or for the larger system via a PLC.

The resultant weighing system provides a very high degree of information exchange at a cost level, which makes it very attractive for the small to medium scale operation.

Back to top