The Tektronix VX4801 is a 48-channel isolated digital I/O module for VXIbus-based data acquisition and control systems. It delivers optically isolated, bidirectional TTL/CMOS-compatible digital I/O organized as six independently configurable 8-bit bytes, making it ideal for industrial and laboratory test environments requiring galvanic isolation and flexible signal routing.
Technical Specifications
Digital I/O Architecture
• 48 channels total, organized as six 8-bit bytes
• Optically isolated, bidirectional configuration
• TTL or CMOS compatible signal levels
• 22 kΩ pull-up resistors to +5V on all I/O and handshake lines
• Output sink current: up to 24 mA per channel
• Input pull-down power consumption: 227.6 µA at 5V
• Programmable active-high or active-low logic sense
Interface and Integration
• VXIbus message-based interface (VXI revision 1.4)
• WSP protocol support
• VXIplug&play driver support enabled
• National Instruments NI-488.2M compatible
• Hardware revision 671-3439-01; Manufacturer ID BFFC; Device ID F4DE
• Firmware version 1.00 and above (1.5 observed)
– Key Features
• Optical isolation eliminates ground-loop issues and protects connected circuits
• Independent byte-level configuration allows mixed input/output operation within a single module
• 24 mA output drive suitable for driving LEDs, relays, and industrial logic circuits
• Integrated pull-up biasing simplifies open-drain interfacing
• Power-on self-test ensures module integrity before operational deployment
• 10-minute warm-up period recommended before measurement verification
– Typical Applications
• General-purpose digital I/O for test and measurement systems
• Functional IC, LCA, and ASIC testing
• PCB module and card functional validation
• Boundary scan research and development
• Industrial control and status monitoring interfaces
– Compatibility & Integration
The VX4801 integrates into VXI system architectures with message-based control and operates under NI LabVIEW and equivalent software environments. Proper ventilation and power management are essential; the module must not operate with covers removed, in wet conditions, or explosive atmospheres.
