Aeroflex / Tektronix / CDS 53A-431B Quad UART RS-232/RS-422 Module

The Aeroflex/Tektronix/CDS 53A-431B is a quad UART module that interfaces up to four external serial devices to a CDSbus system. It supports both RS-232 and RS-422 communication standards with independent, simultaneous full-duplex operation across all four channels. Each channel is individually configurable for baud rate, word length, stop bits, parity generation/checking, and flow control via ASCII programming commands, with settings retained in non-volatile memory.

Technical Specifications

• Channels: Four independent asynchronous UART channels


• Interface Standards: EIA RS-232C (1969), EIA RS-422A (1978)


• Baud Rates: 10, 300, 600, 1200, 1800, 2400, 4800, 9600, 19200 baud (per channel, software selectable)


• Word Length: 5, 6, 7, or 8 bits per channel


• Stop Bits: 1, 1.5, or 2 bits per channel


• Parity: Odd, even, or none per channel


• RS-232 Signal Levels: Transmit ±9V to ±14V (3 kΩ load); Receive +3V to +30V (space), −30V to 0V (mark)


• RS-422 Signal Levels: Transmit 2V to 5V differential (100 Ω load); Receive 200 mV to 30V differential


• Data Buffers: Transmit and receive each programmable from 0 to 4 KBytes in 1 KByte increments


• On-Card Memory: 32 KBytes


• Flow Control: RTS/CTS and XON/XOFF support


• Interrupts: Programmable for specific character, buffer size, overflow, link error (including parity), XON/XOFF


• Self-Test: Per-channel loopback under program control


• Status Indicators: LEDs for TXD, RXD, CTS, DCD, DTR, RTS, and programming errors

Key Features

• Per-channel switch selection between RS-232 and RS-422


• Selectable data inversion and echo per channel


• Parity and receive error detection


• ASCII-based programming interface


• Dimensions: 197 mm H × 13 mm W × 221 mm D


• Operating Temperature: −10°C to +65°C


• Storage Temperature: −40°C to +85°C


• Humidity: <95% RH non-condensing

Typical Applications Multi-channel serial communication in test systems, data acquisition platforms, and legacy equipment interfaces requiring mixed RS-232/RS-422 connectivity within CDSbus environments.

Compatibility & Integration Designed for 53/63 Series card cage modules. Interfaces directly to CDSbus system controllers.