Keithley 705 Data Acquisition Mainframe

The Keithley 705 Data Acquisition Mainframe is a modular switching and data acquisition hub engineered for automated test systems requiring flexible channel configuration and scalable expansion. It accepts interchangeable plug-in scanner cards and supports daisy-chaining up to four slave units with a master, delivering channel densities up to 100 2-pole channels. The mainframe integrates IEEE-488 bus control, digital I/O triggering, and a battery-backed real-time clock for time-stamped measurements and offline operation across research, development, and production environments.

– Technical Specifications

• Modular Architecture: Accommodates two plug-in scanner cards; matrix configurations expandable by connecting cards (e.g., 4×10 or 8×5)
• Internal Clock: Battery-backed; clock accuracy better than 1 minute per month; supports time-dependent procedures
• Battery Backup: 3.6 V rechargeable nickel-cadmium; provides up to 1 month data retention when powered off
• Scan Rate: Selectable from 10 ms (100 channels/second) to 999.999 seconds (1 channel/16 minutes)
• Switching Speed: Less than 2 ms actuation time, exclusive of mainframe overhead
• Relay Drive: Minimum 350 mA; 200 mA typical at 400 Hz operation and 35°C maximum ambient
• Relay Life: 10^7 closures at maximum signal levels; 10^5 closures for cold switching

– Key Features

• Channel Configurations per Card: 1-pole (20 channels), 4-pole (10 channels), or matrix (4×5 per card with 3-pole Form A relays)
• Digital I/O: Open-collector port with four BNC connectors: External Trigger, Alarm Out/Serial-In, Channel Ready, and Serial Out (TTL compatible)
• Expansion: Daisy-chaining supports up to five mainframes (1 master + 4 slaves) for significant system scaling
• IEEE-488 Compliance: Full integration with automated test equipment via standard bus protocol

– Typical Applications

• Multi-channel switching for automated test systems
• Four-wire resistance measurement configurations
• Matrix switching for complex signal routing
• Time-stamped data logging with offline clock retention

– Compatibility & Integration

IEEE-488 interface enables control from programmable test systems. TTL-compatible digital I/O supports external triggering and alarm outputs. Compatible with all Keithley scanner card modules designed for the 705 architecture.