ControlLogix - Model HI 1756-2WS -Dual Weighing Scale Module

The HI 1756-2WS conditions and digitizes the weight signal fifty times per second with over eight million counts of resolution over a differential signal range of -2.5 to 17.5mV. 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 over sizing of the load sensors while retaining a high level of usable resolution.

The module supplies 5 volts of DC excitation to drive up to four 350 ohm load sensors or load cells associated with a single scale (four additional for a second scale). It will support additional load cells with an external power supply.

The HI 1756-WS supports the use of the producer/consumer technology in the ControlLogix system to transmit data. This type of communications is an intelligent data exchange in the system where the module produces data without having to be polled.

Hardy’s HI 1756-WS is available as a single slot, single or dual scale, weigh scale module that mounts in an Allen-Bradley ControlLogix Chassis. It reads weight and diagnostic data from strain gauge load sensors or load cells and communicates this data over the I/O chassis Backplane to the ControlLogix Processor. The HI 1756-WS module reduces installation cost and increases speed since no external stand-alone scale instrument with a wired communications link to the PLC is needed.

The HI 1756-WS conditions and digitizes the weight signal fifty times per second with over one million counts of resolution over a differential signal range of 0 to 15mV. 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 over sizing of the load sensors while retaining a high level of usable resolution. The module supplies 5 volts of DC excitation to drive up to four 350 ohm load sensors or load cells associated with a single (-WS), or eight load cells associated with a dual (-2WS) scale. It will support additional load cells with an external power supply.

The HI 1756-WS supports the use of the producer/consumer technology in the ControlLogix system to transmit data. This type of communications is an intelligent data exchange in the system where the module produces data without having to be polled.

Two or three bi-color LEDs on the module’s front panel report functional characteristics. Being a true ControlLogix module the HI 1756-WS supports removal and insertion under power.

C2 Electronic Calibration
C2 enables electronic calibration of the weigh system without test weights. This saves system start-up costs and aggravation. Of course, even if C2 certified load sensors are not used, the system can still be calibrated the slow, traditional way using certified test weights.

Waversaver
Waversaver eliminates the effects of unwanted plant vibration on or around the scale by permitting the weigh module to “see” through the unwanted vibration signals - as low as 0.25Hz - while yielding a stable actual reading.

Integrated Technician
Integrated Technician, used in conjunction with an IT Junction Box, provides built-in system diagnostics that enable you to troubleshoot and diagnose your weighing system. You can read individual load sensor voltages and weights, make comparisons, and isolate individual system components for quick and easy troubleshooting.

The Button
With one push of a button the weigh scale module automatically calibrates the C2 certified weighing system, making it ready for use. This saves system start-up time costs and aggravations.

Power
Provided from the backplane of the rack: +5Vdc, +24Vdc

Backplane Current
< 1 Amp @ 5Vdc 5W
< 0.0125 Amp 0.3 @ 24Vdc with 4 350 ohm L.C.

Inputs
Signal: -0.3mV through +15.3 mVdc
Sense: +5Vdc
C2 Electronic Calibration

Outputs
Excitation 5Vdc to 8.75Vdc

Common Mode Rejection
100dB at or below 60 Hz (minimum)

Resolution
Internal, 1:8,388,608

Conversion Rate
50 updates per second

Vibration Frequency Rejection
0.25 Hz and above in 5 selectable steps
WAVERSAVER

Weight
1.1 lb (0.5 kg)

Environmental Conditions
Operating Temperature: 0 to 60°C (32 to 140°F)
Storage Temperature: -40 to 85°C (-40 to 185°F)

Relative Humidity
5 to 95% (non-condensing)

Weighing Modes
Net, Gross, Rate-of-Change

Calibration
Electronic (C2)
Traditional (test weights)

Averages
1-255 user selectable in single increments

Indicators
“OK” Module Status, tri-color LED
“Scale 1” Functional Data, tri-color LED
“Scale 2” Functional Data, tri-color LED

Approvals
UL, CUL, CE

Warranty
Two-year warranty against defects in workmanship

Options

Remote Termination Assembly (-RTA)
The weigh scale module optional Remote Termination Assembly provides connection points between the cable assembly to the module and individual wires from the junction box, or load sensors, of up to two scales. The RTA is designed for standard DIN mounting rails or standoffs. With an HI 1756-RTA configuration, the weigh scale modules can be replaced without disturbing the wiring.

Cable (-C6 -DC6)
Hardy provides an optional 6-foot (1.8m) cable assembly from the weigh scale module to the remote termination assembly for both single and dual configuration.