Technical Specifications
| Parameter Name | Parameter Value |
|---|---|
| Product Model | 1756-DICAM |
| Manufacturer | Allen-Bradley (Rockwell Automation) / Digitronic CamCon |
| Product Type | Digital Cam Switch Unit / PLS+ Boolean Processor |
| Platform | ControlLogix 1756 |
| Outputs | 24 (electrolytically separated) |
| Inputs | 8 (electrolytically separated) |
| Programmable Cams | 1,200 standard (expandable to 4,000 / 10,000) |
| Switching Speed | 70 µs cycle time (adjustable) |
| Delay Compensation | 0 to 9,999.9 ms |
| Storage Options | 16 KB / 48 KB / 128 KB EEPROM |
| Programs Supported | 32,768 |
| Backplane Power | 450 mA at 24 VDC |
| Output Current | 0.2 A per output; 0.4 A at 50% duty cycle |
| Interface | ControlLogix backplane; optional RS-485 |
| Operating Temperature | 0°C to 55°C |
| Protection Rating | IP20 |
| Weight | Approximately 0.35 kg |
Main Features and Advantages
Independent High-Speed Switching Processor: The 1756-DICAM functions as a dedicated coprocessor that executes cam switching logic independently of the ControlLogix controller’s scan cycle, achieving reaction times of 70–100 microseconds . This architecture eliminates the latency associated with backplane communication and controller program execution, ensuring that output transitions occur at precisely the programmed angular or linear positions regardless of controller loading. For high-speed machinery where milliseconds of delay translate to significant positional error, the 1756-DICAM provides a level of deterministic response that standard PLC output modules cannot match.
Electronic Replacement for Mechanical Cam Assemblies: The 1756-DICAM eliminates the mechanical wear, lubrication requirements, and time-consuming adjustment procedures associated with physical cam switches and limit switches. Cam positions, on/off angles, and output assignments are configured electronically, allowing changes to be made in minutes rather than hours of mechanical disassembly and recalibration. The module’s support for 1,200 cams as standard—far exceeding what is practical with mechanical camshafts—enables complex multi-output sequencing that would be mechanically infeasible with physical hardware .
Delay Time Compensation for Speed-Dependent Positioning: The 1756-DICAM includes programmable delay time compensation that accounts for the response lag of downstream actuators such as solenoid valves, contactors, and pneumatic cylinders . Because actuator dead time causes positioning errors that vary with machine speed, the module allows a compensation value to be configured so that the switching signal is advanced or delayed to align the actual physical action with the desired position. This capability is particularly valuable in packaging, printing, and converting applications where adhesive application, cut-off, or registration must occur at a precise point on a moving web regardless of line speed.
Comprehensive Diagnostic and Integration Features: The 1756-DICAM provides 32 front-panel status LEDs for immediate visual indication of input, output, and module health, simplifying troubleshooting without requiring a programming terminal . The module integrates with the ControlLogix environment through an RSLogix 5000 configuration file, and supports data exchange with the controller for recipe changes, cam set selection, and diagnostic monitoring. The optional RS-485 interface enables local testing and configuration access, while the module’s 32,768 program capacity accommodates extensive cam set libraries for product changeover without reprogramming .
Application Field
Metal Forming and Eccentric Press Control: The 1756-DICAM is specifically engineered to support eccentric press applications, where precise angular synchronization between the crankshaft position and auxiliary functions—such as material feed, lubrication, and part ejection—is critical to product quality and die protection . The module’s dedicated eccentric press software and sub-100-microsecond response time ensure that switching commands occur at the exact crank angle required, even at high press speeds where mechanical cam systems would introduce unacceptable timing variation. The 1756-DICAM replaces the wear-prone mechanical camshafts and limit switches traditionally used in these machines with a maintenance-free electronic solution.
Packaging and Web Converting Machinery: In packaging equipment, printing presses, and web converting lines, the 1756-DICAM controls functions that must repeat at precise intervals relative to a moving web or rotating tool. Adhesive application, cut-off registration, perforation, and folder activation all depend on switching signals that are synchronized to machine position rather than time. The module’s delay compensation feature allows these operations to maintain registration accuracy across the full speed range of the machine, from crawl speed during setup to maximum production rate . The 1756-DICAM is equally applicable to rotary die-cutting, labeling, and form-fill-seal equipment where electronic cam control replaces mechanical linkages.
Rotary and Indexing Machinery: The 1756-DICAM supports rotary machinery applications including bottling lines, cap feeders, labeling stations, and high-speed assembly turrets, where multiple outputs must activate and deactivate at specific angular positions during each revolution. The module’s 24 outputs and 1,200-cam capacity allow a single 1756-DICAM to replace numerous mechanical switches and timers, reducing wiring complexity and panel space. For machines with variable-speed operation, the electronic cam approach ensures that switching positions remain consistent regardless of throughput, eliminating the speed-dependent timing errors inherent in timer-based control.
