Aeroflex / Tektronix / CDS 53A-351 Relay Switching Module

The Aeroflex / Tektronix / CDS 53A-351 Relay Switching Module is a PCB assembly that provides signal routing and switching within the CDS 53/63 Series card cage systems. The module contains 24 SPST relays controlled via ASCII character commands from a system controller, enabling automated random opening or closing of individual relay channels. It delivers low signal distortion performance for instrumentation and test applications requiring high-speed relay switching.

Technical Specifications

• Relay Configuration: 24 × Single Pole, Single Throw (SPST)


• Switching Speed: Up to 100 operations per second


• Dwell Time: Minimum 4 ms


• Power Supply: 5 V dc (4.75 V dc to 5.25 V dc)


• Current Draw: 0.72 A maximum quiescent; 0.75 A peak


• Operating Temperature: 0°C to +50°C


• Storage Temperature: -40°C to +85°C


• Humidity: Less than 95% R.H. non-condensing


• Weight: Approximately 0.4 kg (0.9 lbs)


• Form Factor: Standard CDS 53/63 Series card slot PCB assembly

Key Features

• ASCII character command interface for software-controlled relay actuation


• LED indicators and software-interrogatable self-test capability to verify individual channel states


• Integrated power and cooling supplied by the 53/63 Card Cage


• Low signal distortion design for precision measurement and switching applications

Typical Applications

• Automated test equipment signal routing


• Instrumentation switching and multiplexing


• High-speed relay-based signal selection

Compatibility & Integration The 53A-351 integrates directly into CDS 53/63 Series systems, working with communications cards such as the 53A-128 via standard command sequences (example: "@01C9" closes relay 9). Analog cabling designed for relay switching modules connects the card to external signal paths.