NI SCB-68 Shielded 68-Pin I/O Connector Block

The NI SCB-68 is a shielded 68-pin I/O connector block that serves as a critical interface for National Instruments DAQ devices. It combines a 68-pin male SCSI connector with 68 screw terminals and breadboard areas to support data acquisition, signal conditioning, and custom circuit integration. Shielded construction minimizes noise interference in laboratory and industrial measurement environments. The SCB-68 accommodates onboard signal conditioning including filtering, voltage attenuation, thermocouple measurements with cold-junction compensation, 4 to 20 mA current input measurement, and open thermocouple detection through integrated component pads.

– Technical Specifications

Connectivity
• 68-pin male SCSI connector (68-pin VHDCI on HSDIO variants)
• 68 screw terminals for direct I/O signal access
• Two general-purpose breadboard areas for custom circuitry
• Component pads supporting signal conditioning for analog input, analog output, and PFI 0 signals

Electrical Performance
• Power consumption: 1 mA typical at +5 VDC (no signal conditioning); maximum 800 mA from host
• +5V supply fuse: 800 mA, 250 V, 5×20 mm
• SMT PTC fuse: 1.10 A at 8 VDC
• SCB-68A includes resettable electronic fuse

Temperature Sensor
• Output: 10 mV/°C
• Accuracy: ±1.0 °C over 0 to 110 °C range
• Onboard cold-junction compensation for thermocouple inputs

Physical Specifications
• Dimensions: 7.7 × 6.0 × 1.8 inches (19.6 × 15.2 × 4.6 cm)
• Weight: 13 oz (0.37 kg)
• Screw terminal wire gauge: 14–30 AWG

– Key Features

• Shielded construction for noise rejection
• DIP switch configuration (S1–S5) for signal type and mode selection
• Thermocouple support with open-circuit detection and input filtering
• 4 to 20 mA current input measurement capability
• RC filtering for analog inputs
• Voltage attenuation options
• Dual breadboard areas for prototyping and component integration

– Typical Applications

Data acquisition systems, analog and digital signal conditioning, thermocouple and current loop measurement, laboratory test automation, and industrial sensor interfacing.

– Compatibility & Integration

The SCB-68 interfaces with 68-pin and 100-pin National Instruments DAQ devices, enabling rapid system deployment and flexible signal routing in multifunction measurement platforms.