Remote I/O

Allen-Bradley Remote I/O (RIO) interface available for most of Hardy's weight controllers

Under license from the Allen-Bradley Corporation, Hardy Instruments Inc. has developed a Remote I/O Interface for its Weight and Rate Controllers.

The interface is fast, field proven, requires minimal wiring, requires no special software drivers, and is standard on many Allen-Bradley programmable controllers. Setting each address and baud rate in the instrument, connecting three wires, and writing some ladder logic is all that is needed to begin communicating weighing parameters to and from a Hardy Instruments controller.

Each Hardy Instruments’ controller represents a quarter (1/4) rack of discrete I/O (32 bits in the PLC Output and Input image files) to the scanning PLC and supports both discrete and block transfers. The PLC continually exchanges 32 bits of its PLC Input Image Table and 32 bits of its Output Image Table with each 1/4 rack device. In a 1771 I/O Rack, these bits would normally be transferred from and to discrete input and output modules. For the weight controller, the Output Image bits are used to send commands to the weight controller and the Input Image bits return weight data and scale status bits. These actions are referred to as “discrete writes and “discrete reads”. The user is also able to exchange blocks of data with a 1/4 rack device via Block Transfer instructions in the PLC ladder logic program. These commands are referred to as “block writes” and “block reads”. The host programmable controller can access all configuration and weighing parameters in the Hardy controller, including performing scale calibration. The Hardy controller can be used as a local display and keyboard for weighing parameters, or function as a blind controller properly digitizing the load sensor signal and providing responsive set point control.

Using the Remote I/O interface shortens development time and provides the most functional weighing interface available for your Allen-Bradley programmable controller.  

HI 4050 Remote I/O

In the HI 4050 Weight Controller, the RIO network has two modes of operation:

• Standard HI 4050: in this mode, the mapping is used to configure the network.
• HI 2151/30: in this mode, an HI 2151/30WC-B8 or HI 2151/20WC-B8 with RIO can be replaced by an HI 4050 without having to change your PLC to 2151 Series operating software. The only exceptions are that the HI 4050 does not support relay output, totalizer or peak hold functions.

Note: All certifications for this Remote I/O option when used in the HI 4050 Series controllers are pending.

Common Applications

Hardy controllers can be used in conjunction with Allen-Bradley programmable controllers to tackle a variety of process control needs. The most basic use of the interface is to simply allow the programmable controller to read weight data from one or more Hardy weight controllers. In addition to reading weight some other applications are:

• Filling
• Dispensing
• Batch Weighing Control
• Monitoring Rate of Flow
• Evaluating Totalized Weight
• Check Weighing
• Weight Level Alarming