Which serial communication standard is used in serial data acquisition systems when the data location is at a distance?

Which serial communication standard is used in serial data acquisition systems when the data location is at a distance?

• A. RS422
• B. RS423
• C. RS232
• D. RS231

Answer: (C)

When data must travel a distance, signal integrity becomes the main challenge. RS-232 uses single-ended signaling with a reference to ground, which works fine for short cables but becomes unreliable over longer runs due to noise and voltage drop. RS-423 can extend a bit further than RS-232 but still isn’t as robust for long distances or multi-device setups. RS-422, on the other hand, uses differential signaling on balanced pairs, which cancels common-mode noise and allows much longer cable lengths with better reliability. It also supports longer links and, in many configurations, multiple devices on the same bus, which is advantageous for serial data acquisition systems spread out over a distance. Therefore, when the data location is at a distance, RS-422 is the appropriate choice among these options. (RS-231 is not a standard serial interface.)

When data must travel a distance, signal integrity becomes the main challenge. RS-232 uses single-ended signaling with a reference to ground, which works fine for short cables but becomes unreliable over longer runs due to noise and voltage drop. RS-423 can extend a bit further than RS-232 but still isn’t as robust for long distances or multi-device setups. RS-422, on the other hand, uses differential signaling on balanced pairs, which cancels common-mode noise and allows much longer cable lengths with better reliability. It also supports longer links and, in many configurations, multiple devices on the same bus, which is advantageous for serial data acquisition systems spread out over a distance. Therefore, when the data location is at a distance, RS-422 is the appropriate choice among these options. (RS-231 is not a standard serial interface.)