
Description:
The 1756-HSC is a two-channel high-speed counter module in the Allen-Bradley 1756 ControlLogix family, manufactured by Rockwell Automation for direct, controller-independent counting of fast pulse-train signals in industrial automation systems. Each counter accepts three inputs (A, B and Z for gate/reset) and drives two sourcing DC outputs per channel, so one single-slot module captures quadrature encoder, proximity-sensor and photoelectric feedback at up to 1 MHz in counter mode while delivering high-speed output control in parallel.roccommerce.net+1
Configured natively inside Studio 5000 Logix Designer and occupying one standard 1756 chassis slot, the 1756-HSC offloads pulse accumulation, frequency measurement and preset-triggered output switching from the controller scan cycle — protecting count integrity on applications where even a single lost pulse is unacceptable.rockwellautomation.com
Application Scenarios:
Picture a high-speed converting line producing perforated film rolls: a rotary encoder feeds 4 000 pulses per revolution into the control system, and a knife must fire within a fixed number of counts — every pass, every shift, without dropping a pulse. The engineering pain points are instantly recognizable to anyone who has tried to wire a fast pulse train into a standard digital-input card: scan-cycle latency that misses pulses at high frequency, count rollover errors, no hardware-based preset triggering, and a knife output that fires late because the controller was busy with other tasks. The 1756-HSC was engineered precisely for this class of application — pulse counting happens entirely on the module at up to 1 MHz in counter mode (250 kHz in encoder X4 mode), the Z input provides hardware gate/reset without controller intervention, and the four sourcing outputs fire on preset values set directly in the module’s configuration, independent of controller scan timing.roccommerce.net+1
The 1756-HSC therefore becomes the natural choice for flow totalizers on turbine meters, length-cut counters on rotary shears, batch counters on bagging machines, overspeed detection on rotating equipment, and registration tracking on print-and-apply labelers — anywhere the pulse train is faster than a standard DC input module can reliably catch, and anywhere a hardwired preset output is needed without PLC latency.industrialmonitordirect.com+1
Parameter:
| Main Parameters | Value / Description |
|---|---|
| Product Model | 1756-HSC (Bulletin 1756, ControlLogix) |
| Manufacturer | Allen-Bradley – Rockwell Automation |
| Product Category | High-speed counter module (specialty I/O, single-slot) |
| Number of Counters | 2 independent hardware counter channels |
| Inputs per Counter | 3 (A, B, Z — where Z is gate/reset), 6 differential DC inputs total |
| Outputs | 4 sourcing DC outputs (2 points per group) |
| Input Frequency, Max | 1 MHz in counter modes (A input); 500 kHz in rate-measurement mode; 250 kHz in encoder X1/X4 mode; 70 Hz with filter enabled |
| Count Range | 0 to 16 777 214 (24-bit) |
| Operating Voltage Range | 5 V mode: 4.5–5.5 V DC; 12/24 V mode: 10–26.4 V DC |
| Backplane Current Draw | 300 mA @ 5.1 V; 3 mA @ 24 V; total backplane dissipation 1.6 W |
| Power Dissipation / Thermal | 3.5 W max @ 60 °C (12 BTU/hr) |
| Isolation Voltage | 250 V continuous (input group-to-backplane); 125 V (input group-to-input group); basic insulation |
| Dimensions / Slot Width | 144.5 × 34.6 × 130.2 mm (H × W × D); occupies 1 chassis slot |
| Removable Terminal Block | 1756-TBCH (cage-clamp) or 1756-TBS6H (spring-clamp); wire 0.33–2.1 mm² (22–14 AWG) |
| Operating / Storage Temp | 0 to 60 °C operating; −40 to 85 °C storage; 5–95% RH noncondensing |
| Temperature Code / Keying | T4 (North American, IEC, ATEX); electronic software-configurable module keying |
| Certifications | c-UL-us, CSA, CE, KC; Class I Div 2 Groups A,B,C,D; ATEX; marine-rated external filter option supported |
