HI 1771WS

OverviewSpecificationsDocs & Programs
HI 1771WS


Note:  The HI 1771WS is a legacy product that is no longer available.  This page is provided for users who may need to access the Installation and Operations manual and any software updates.

Support for Allen-Bradley PLC5

The Hardy Process Solutions HI 1771-WS is a single slot weigh scale module that mounts in an Allen-Bradley 1771 Universal I/O chassis. It reads weight data from strain gage load sensors and communicates this data over the I/O chassis backplane to one of Allen-Bradley's PLC-5 family of Programmable Controller Processors. The HI 1771-WS module reduces installation costs as it needs no external stand-alone scale instrument, and provides a wired communications link to the PLC.

The HI 1771-WS conditions and digitizes the weight signal 20 times per second with over one million counts of resolution over a differential signal range of 0 to 30mV. It then transmits the selectable Gross, Net and/or Rate-of-Change data to the processor. This high resolution allows the module to tolerate large dead loads and oversizing of the load sensors while retaining a high level of usable resolution. The module supplies 10V of DC excitation to drive up to four 350 ohm load sensors, or load cells, associated with a single scale. It will support additional load cells with an
external power supply.

Two independent firmware set points are included that provide control capability. Each have a separate preact
to compensate for in-flight material as well as system response delays along with a deadband that compensates for potential relay chatter.

Two bi-color LEDs on the module's front panel report its functional characteristics. Calibration can be performed in traditional ways (hard cal), or by our exclusive C2®, Second Generation Calibration, which enables electronic calibration in seconds without test weights.