RS232compliant

RS232compliant refers to hardware or interfaces that conform to the RS-232 serial communication standard. RS-232, standardized as RS-232-C by the Electronics Industries Association and later maintained in various editions, defines the electrical and mechanical characteristics for serial data exchange between data terminal equipment (DTE) and data communications equipment (DCE). Compliance indicates that devices can connect and communicate using a traditional serial port arrangement over copper wiring.

Electrical signaling and levels: The standard specifies single-ended, bipolar signaling in which logical states are represented by voltages relative to ground. A typical “space” is +3 to +15 V and a “mark” is -3 to -15 V; idle state is mark. Modern implementations may tolerate a wider range, but RS-232 devices should interpret voltages within these ranges. Signaling is asynchronous, requiring a start bit, data bits, optional parity, and one or more stop bits per frame.

Connectors and pinouts: RS-232 commonly uses DE-9 (9-pin) or DB-25 (25-pin) D-sub connectors. Essential signals include TXD, RXD, and GND; many devices also use handshaking lines such as RTS, CTS, DTR, DSR, DCD, and RI for hardware flow control, though some implementations omit them.

Data format and speed: Asynchronous transmission is typically 7 or 8 data bits, with parity options (even, odd, or none) and one or two stop bits. Common configurations are 8 data bits, no parity, 1 stop bit (8N1). Baud rates range from 110 bps to several megabits per second in specialized hardware, with higher speeds reducing maximum cable length.

Modern usage and compatibility: Although USB and Ethernet have largely supplanted RS-232 in consumer devices, RS-232 remains in use for industrial, laboratory, and embedded systems because of its simplicity and robustness. A device advertised as RS232compliant should implement the standard’s electrical levels, signal directions, and common connector types, or provide a compatible adapter.