Overview
The Allen-Bradley 8500-HDM1 high-density I/O module is a dedicated PC board designed to expand I/O capability on 9/Series and 9/260 CNC controllers. This servo add-on module delivers 24 VDC logic-level signal processing for both analog and discrete inputs/outputs in demanding machine tool environments. Part number 160579 (Revision 03) and 156730 (Revision 02) are interchangeable variants of this discontinued but still-serviceable automation component.
Key Features
- 24 VDC supply voltage for standard industrial logic levels
- High-density I/O architecture reduces panel space requirements
- Optical isolation support with OP23/OP24 connectors for noise immunity
- DIP switch configuration for flexible I/O mapping
- Screw terminal connections for field wiring
- Passive cooling design—no forced ventilation required
Technical Specifications
- Supply Voltage: 24 VDC
- Module Type: High-Density I/O (Servo Add-On)
- Part Numbers: 160579 (Rev. 03), 156730 (Rev. 02)
- Operating Temperature: 0 to 60°C (32 to 140°F)
- Relative Humidity: 5 to 95% (non-condensing)
- Weight: 3.38 lbs
- Environmental Rating: IP 20 (enclosed installation recommended)
- Connection: Screw terminals with DIP switch configuration
- Status: Discontinued by manufacturer
Typical Applications
- 9/Series and 9/260 CNC controller I/O expansion
- Machine tool control signal conditioning
- Servo motor feedback and enable logic
- Legacy automation system retrofit and repair
- Spindle speed control and coolant pump switching
Compatibility & Replacements
The 8500-HDM1 is purpose-built for Allen-Bradley 9/Series CNC controllers (9/230, 9/260, 9/290 models). Both revision levels of the PC board (160579 Rev. 03 and 156730 Rev. 02) are functionally equivalent and may be used interchangeably. As this module is discontinued, replacement stock is increasingly difficult to source; spare units are essential for minimizing downtime in legacy systems. For modern replacements, consult your systems integrator about current-generation distributed I/O solutions.
