The Stanford Research Systems SX199 Optical Interface Controller is a communications bridge designed to connect up to four SRS instruments equipped with serial optical interfaces to a host computer via GPIB, RS-232, or Ethernet. The controller delivers complete electrical isolation between the PC and connected instruments through optical cable transmission, eliminating ground loops and transient coupling in sensitive measurement systems. It supports SR2124 analog lock-in amplifiers, CS580 current sources, DC205 voltage sources, and other compatible SRS devices with optical serial interfaces.
Technical Specifications
Optical Ports & Connectivity
• Four serial optical ports with Avago Versatile Link duplex connectors (HFBR-4506Z mating)
• 660 nm nominal wavelength
• Standard 3 m fiber optic cables (HFBR-RMD003Z); 10 m option available (HFBR-RMD010Z)
Remote Interfaces
• GPIB (IEEE-488.2), RS-232, Ethernet (10/100 Base-T, auto-negotiating)
• Interface selection via rear-panel DIP switches
RS-232 Interface
• 9-pin Type D female connector, DCE configuration (Tx pin 3, Rx pin 2)
• Fixed 8 data bits, 1 stop bit, no parity, no hardware flow control
• Selectable baud rate: 9600 or 57600 bps (DIP switch selectable; power cycle required)
Debug Port
• RS-232, 9-pin Type D female connector, DCE configuration
• Mirrors all data including link mode, native commands, and queries
• Baud rate matches main RS-232 port setting
Power & Environmental
• Universal AC input: 90–260 VAC, 47–63 Hz
• Power consumption: 25 W
• Operating temperature: 0 °C to 40 °C, non-condensing
• Weight: 5 lbs
Physical
• Dimensions: 8.25″ W × 4″ H × 11″ D
• Single and double rack-mount configurations available
– Key Features
• Optical isolation eliminates PC-to-instrument coupling and ground loop issues
• Multiple instrument support on single controller reduces cable clutter
• DIP switch configuration for straightforward interface selection
• Debug port for real-time protocol monitoring and troubleshooting
• LED status indicators for power, port, and interface activity
– Typical Applications
• Precision optical research and measurement requiring galvanic isolation
• Multi-instrument control in systems sensitive to EMI and ground transients
• Laboratory automation with legacy and modern SRS instruments
• Data acquisition setups where noise immunity is critical
– Compatibility & Integration
The SX199 integrates with SR2124 lock-in amplifiers, CS580 current sources, and DC205 voltage sources. Standard GPIB, RS-232, and Ethernet connectivity interfaces with existing laboratory software and control systems.
