Allen-Bradley 1756-HSC High Speed Counter Module

The Allen-Bradley 1756-HSC is a counter module that is used to perform high-speed counting for industrial applications. This module has selectable modes such as the frequency mode, or the counter mode for processing input signals. The counter mode is set as the default mode which can update data every 2 milliseconds. Users can change the storage of the count values because the 1756-HSC module uses the user-configured presets to evaluate it against the count values. This gives the module a faster response time for activating outputs, compared to when an evaluation is done in the controller. Preinstalled configuration tags are available with the 1756- HSC module and these tags will decide whether the pulse that is counted will be an accumulated count, ranging from 1 to 16 million, or a positive or negative frequency, depending on the rotation’s direction.

Technical specifications for 1756-HSC

ManufacturerRockwell Automation

BrandAllen-Bradley

Part Number/Catalog No.1756-HSC

SeriesControlLogix

Inputs3 per Counter

Module TypeHigh Speed Counter Module

Outputs4-Point

Signal Frequencies1 MHz in counter modes (A input); 500 KHz in rate measurement mode (A input); 250 KHz in encoder mode (A/B inputs, X1 or X4); 50Hz with debounce filter enabled

Operation ModesCounter, Rate Measurement, Encoder, Debounce Filter

Backplane Current (5Volts)300 milliamps

Backplane Current (24 Volts)3 milliamps

Power Dissipation (Max)5.6 Watts at 60 Celsius

Count Range0-16, 214, 777

Removeable Terminal Blocks1756-TBCH, 1756-TBS6H

LocationChassis (Any Slot)

Slot Width1

The 1756-HSC module has 3 inputs per counter (A, B, and Z for gate reset) and 4 outputs (2 points per group) that are available for each module. The maximum input frequency is 1 megahertz in the counter mode (A Input), 500 kilohertz in the rate measurement mode (A Input), 250 kilohertz in the encoder mode (A/B Inputs, X1 or X4) and 70 Hertz with the filter enabled. Additionally, each counter channel can assign any number of output channels, with each output having as much as 2 turn-off preset values. Outputs on the 1756-HSC module can be turned on or off at the user’s discretion. The operating voltage range at 5 Volts operation is from 4.5 to 5.5 Volts DC and 10 to 31.2 Volts DC for 12/24 Volts operation, the total backplane power dissipation is 1.9 Watts, and the maximum power dissipation is 5.6 Watts at 60 degrees Celsius. The 1756-HSC module is commonly used together with the Allen-Bradley 845 incremental encoder, the PHOTOSWITCH series 10,000 photoelectric sensors, and the Allen-Bradley Bulletin 872 3-wire DC proximity sensor.