RS-232

RS-232 is an interface standard for serial data communication established by the Electronic Industries Alliance (EIA). It is formally known as EIA-RS-232 (or simply 232, RS232). Widely employed for connecting computer peripherals that use serial interfaces, RS-232 operates through single-ended transmission, utilizing a signal line (TX for transmission) and a receive line (RX for reception). In contrast to RS-485, RS-232 utilizes non-differential signals, where data values are represented by voltages relative to ground. This characteristic makes RS-232 more susceptible to electromagnetic interference and limits its transmission distance.

While RS-232 was once a standard interface for communication between personal computers and various devices, it has gradually been replaced in some applications due to limitations such as shorter transmission distances, restricted data rates, and vulnerability to electromagnetic interference. Despite this, RS-232 continues to find use in specific applications, with some devices and instruments still supporting the RS-232 interface.

Recommended Debug Tools

TB3016F

TB3000 series Specifications PDF

MSO2116E (w/ analog channels)

MSO2000 series Specifications PDF

MSO3124V (w/ electrical validation)

MSO3000 series Specifications PDF

UART(RS232) Decode

UART(RS232) Electrical Validation

Use an oscilloscope for UART electrical validation to ensure compliance with defined specifications. After an extended burn-in test, the oscilloscope confirms that the electrical characteristics of the signal meet the required standards.

Electrical Validation Solution PDF

Protocol Quick Setup:

1. Click Quick Settings to select a protocol for logic analyzer capture.

2. Select UART(RS232) for decoding.

3. The system provides recommended settings for trigger type, sampling rate, voltage threshold, and channel settings.

4. Click the icon to access the Decode Settings screen.

Decode Settings:

Channel:

Rx: Show Rx data in report window.

Format:

Auto Detect: Set the Baud Rate manually if not selected.

Baud Rate: Data rate (bits per second), and the range is 110 ~ 2M (bps).

Data Bits: 4 to 16 bits.

Polarity: Idle high and Idle low.

Parity: N (None), O (Odd), or E (Even).

Stop Bits: 1 to 2 bit(s).

MSB first: The default is LSB first; click it to change to MSB first.

Waveform Area Settings:

Show scale in the waveform: Display the waveforms with scales.

Report Area Settings:

Report Unknown and Idle: Display the unknown and idle data in the Report Window.

Line Wrap Data: Use 1-2 value (hex) as header of data.

YouTube Video

UART Decoding Examples