Keithley SSIO-24 24-Channel Solid-State I/O Module Board

The Keithley SSIO-24 is a 24-channel solid-state I/O module accessory board that interfaces digital signals in automated test and measurement systems. It has high-speed switching with 4000V rms isolation, enabling precise control and monitoring of AC and DC loads across industrial automation, data logging, and system test applications. The board accommodates four color-coded module types

DC input, DC output, AC input, and AC output - each optimized for specific voltage and current ranges. A 37-position D-Sub connector integrates with host test systems, while onboard LEDs provide real-time I/O status indication. ## Technical Specifications • Model: SSIO-24 • Channels: 24 • Termination: Screw-in terminal blocks accepting 22–12 AWG wire • Interface Connector: 37-position D-Sub • Dimensions: 16" × 4.25" • Isolation Voltage: 4000V rms ## I/O Module Options DC Input (White)

Senses AC or DC voltage, outputs 0 or +5V logic signal DC Output (Red) • SM-ODC5: 3–60V DC, 3.0A max load current • SM-ODC5A: 3–250V DC, 1.0A max load current • Response time: 100 µs (on), 750 µs (off) AC Input (Yellow) • SM-IAC5: 90–140V AC/DC input • SM-IAC5A: 180–280V AC/DC input AC Output (Black) • SM-OAC5: 12–140V AC, 3.5A max load current (SM-OAC5R variant for reactive loads, power factor ≤ 0.5) • SM-OAC5A: 24–280V AC, 3.5A max load current • Response time: 0.5 cycle (on/off) ## Key Features • Miniature solid-state relay modules eliminate mechanical switching wear • Color-coded module types simplify field identification and replacement • Modular architecture supports mixed-mode I/O configurations • LED status indication for each channel • Operating temperature range: –30°C to +80°C • Storage temperature range: –40°C to +100°C • Complies with EN61010-1/IEC 1010 and EU Directive 89/336/EEC ## Power Requirements External power supply required. Current consumption: 180 mA max./115 mA typical (no modules installed); 610 mA max./270 mA typical (with modules installed). ## Typical Applications Industrial control systems, automated test equipment, sensor-based data acquisition, switchable load management, and system validation in manufacturing environments.