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.

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.

The Allen-Bradley 1756-HSC is a High-Speed Counter module that belongs to the 1756 ControlLogix product family. This module is used for counting applications and detecting position or degree of rotation of rotary devices such as a motor.

This module is capable of being used with encoders and pulse generating devices such as metering devices for Flow Totalization and magnetic pick-up sensors to detect the rotation speed of an equipment.

This module has built in Counter and Frequency modes. The selected mode determines the manner on how the pulse will be counted and stored including output behavior.



This module support pulse signals with frequencies of 1 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. The Count range of this module can reach up to a maximum value of 0 - 16,777,214 which can be reset via an external signal or a memory bit which may be triggered manually or automatically.