The Measurement Computing USB-1208LS is a multifunction USB data acquisition device that combines analog input, analog output, digital I/O, and event counting in a single bus-powered unit. It operates directly from USB 1.1 or USB 2.0 ports without requiring external power, making it ideal for portable and lab-based measurement systems requiring flexible channel configurations and multiple acquisition modes.
Technical Specifications
Analog Input
• 8 single-ended channels at 11-bit resolution; 4 differential channels at 12-bit resolution
• Single-ended input range: ±10 V
• Differential input ranges (software-selectable): ±1 V, ±1.25 V, ±2.0 V, ±2.5 V, ±4 V, ±5 V, ±10 V, ±20 V
• Programmable gain amplifier on differential channels with gains up to 20
• Input impedance: 122 kΩ
• Input common-mode voltage: ±10 V (SE mode), –10 V to +20 V (DIFF mode)
• Absolute maximum input: ±40 V to ground
Analog Output
• 2 channels, 10-bit resolution
• Output range: 0 V to 5 V
• Update rates: 100 S/s (single channel), 50 S/s per channel (two channels simultaneous)
• Software-paced mode only
Digital I/O
• 16 lines configured as two independent 8-bit ports (Port A and Port B)
• TTL logic levels
• 47 kΩ pull-up resistors to 5 V (configurable to pull-down via internal jumpers)
• Maximum source current: 5 mA
External Event Counter
• 32-bit resolution
• Maximum input frequency: 1 MHz
• TTL level inputs
Data Acquisition Modes
• Software paced: 50 S/s typical throughput
• Hardware paced (continuous scan): 1.2 kS/s aggregate across up to 8 channels
• BURSTIO mode with 4 kB FIFO: 8 kS/s maximum aggregate sampling rate for sequences up to 4096 samples
• Both hardware-paced and BURSTIO modes support software command or external hardware trigger initiation
– Key Features
• Bus-powered operation via USB eliminates external power supply requirements
• Integrated 82C55 programmable peripheral interface for flexible digital I/O configuration
• Dual acquisition modes optimize throughput for continuous monitoring or burst capture scenarios
• On-board FIFO buffering supports high-speed data streaming to host PC
– Typical Applications
Data logging, sensor interface, signal monitoring, event counting, and automated test systems requiring mixed-signal acquisition without dedicated instrumentation.
– Compatibility & Integration
USB 1.1 and USB 2.0 compatible. Standard TTL and analog voltage interfaces enable direct integration with industrial and laboratory instrumentation.
