HI 1756-nDF

HI 1756-nDF dispenser/filler module for ControlLogix PLCs are the easy answer to a variety of material feed applications, especially, when speed and accuracy of the feed are paramount to the process.

Material Feed Management by Weight for ControlLogix® PLCs

The HI 1756-nDF ControlLogix Dispenser/Filler module is the easy answer to a variety of material feed applications, especially, when speed and accuracy of the feed are paramount to the process. The module batches, fills or dispenses aggregates, granulates, liquids or gases, handling the entire feed process.

The internal set point control is moved closer to the process, by taking it out of the PLC and into the module. This eliminates timing issues created by non-deterministic messaging. To compensate for flow rate variations during the feed, real time target (preact) adjustments can be sent from the PLC, or be calculated by the module. Modules come in single or dual scale configurations. Each scale is fitted with a choice of two integrated solid state DC or AC relays to control fast and slow feed rates.

HI 1756-nDF Dispenser, Filler for ControlLogix PLC
The HI 1756-nDF will calculate and transmit gross weight, net weight & flow rate outputs simultaneously. Non-linear flows due to varying densities and head pressures are a thing of the past with its predictive algorithm automatically adjusting the system’s setpoint preact function.

These modules can be inserted and removed under power without disruption of any other modules in the system (racks). This makes it possible to replace a failed module while keeping the rest of the system running. Status indicators are provided on the front of the module for fault status. A status block will provide information to the processor for alarming and troubleshooting.

Visit our Case Studies and Application Notes for more information on material feed management.

Rockwell Add-On-Profile (AOP)

Hardy Process Solutions has the highest level of integration with Rockwell Automation® PLCs, with backplane integration and  Add-on-Profiles (AOPs). These integration tools are designed to provide EASY and seamless setup with Rockwell PLCs, PACs, using RSLogix® or Studio 5000®


Update Rate
• 100 updates per second (10 ms)
• Internal, 1:8,388,608
• Up to eight 350-ohm Full Wheatstone Bridge, Strain Gauge Load Sensor/Cells (5 volt excitation) on one vessel
• 0.0015% of Full Scale
Common Mode Rejection
• 110dB at or below 60 Hz
Common-Mode Voltage Range
• 2.5VDC maximum (with respect to earth ground)
Backplane Input Voltage
• 5 VDC and 24 VDC
Backplane Current Load
• <1 Amp at 5 VDC
• 0.0125 Amps at 24 VDC (with 4-350 Ohm Load Cells)
Backplane Power Load
• < 5W at 5 VDC
• < .3W at 24 VDC with 4-350 Ohm Load Cells
C2® Calibration Signals
• Isolation from digital section 1000 VDC minimum
Cable Lengths
• 1000 feet maximum of C2 authorized cable
• 250 feet maximum of C2 authorized cable (Maximum of 4 load sensors) with IT Junction box.
C2® Maximum Cable Length
• 1000’ for C2, Non C2, or Summing Card
• 250’ for IT
Load Cell Excitation
• 5 VDC +/- 1.15 W maximum
• Isolation from digital section 1000 VDC minimum
Number of Weigh Scale Channels
• HI 1756-1DF 1 Weigh Scale Channel
• HI 1756-2DF 2 Weigh Scale Channels
• 1-255 User-selectable in Single Increments
• Averages current and previous N samples to provide the current weight value
WAVERSAVER® Vibration Immunity
• User Selectable
• Two solid state DC or AC relays per weigh scale channel - For resistive loads only (Form A - Normally Open)
DC Relay
•5 to 30 VDC
- 0ºC to 25ºC: max current = 3A
- 0ºC to 40ºC: max current = 2A
- 0ºC to 60ºC: max current = 1A
Minimum load
• 2mA current
Operating Temperature Range
•0 to 60º C (32º F to 140º F)
Storage Temperature Range
• -40 to 85º C (-40 to 185º F)
• UL
• CE
• Two-year warranty against defects in workmanship

All specifications subject to change without notice. Please
contact the Hardy factory or visit our website for the latest specifications.


Form A- Normally open (for resistive loads only)

HI 1756-1DF
- 2A = 2 AC Relays (1AC relay per channel)*
- 2D = 2 DC Relays (1 DC relay per channel)*

HI 1756-2DF
- 4A = 4 AC Relays (2 AC relays per channel)*
- 4D = 4 DC Relays (2 DC relays per channel)*

*Combination of AC and DC relays available upon request

Hardy Process ToolboxHardy Process Toolbox

The Hardy Process Toolbox is a set of productivity tools that support industrial weighing functions. Each tool saves time, increases accuracy, improves efficiency or reduces risk in process weighing applications, including WAVERSAVER® to eliminate vibration, C2® electronic calibration and Integrated Technician® to name just a few.

The HI 1756-nDF features the following Toolbox technologies:

WAVERSAVER® vibratrion eliminator
Hardy's WAVERSAVER core technology eliminates the effects that surrounding vibration has on the scale weight signal, providing only true data for fast, accurate weight reading.

C2® (or eCAL) Electronic Calibration
The Hardy C2® (or eCAL as it is known in China) core feature provides quick and easy electronic calibration of a weighing system without the need for heavy test weights.

Hardy's INTEGRATED TECHNICIAN (IT) core feature helps you troubleshoot your weighing system and diagnose problems from the front of the instrument or via the PLC. These tests display system weights, voltages, and pass/fail displays to help isolate a problem to the instrument, cabling, or sensors, helping to reduce maintenance costs.

FEED-MASTER is a set of software controls designed to control volumetric and gravimetric feeders.