What are the difference between RS-232, RS-422, RS-485?

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#1

RS-232

Cabling: Single ended

Communication mode: Full duplex

Number of devices: 1 Transmitter, 1 receiver

Max. Data rate: 19.2 Kbps for 50 feet

Signalling: Unbalanced

Max. Distance: 50 feet at 19.2 kbps

Mark (data 1): -5v min to -15 max

Space (data 0): 5v min to 15v max

Output current : 500 mA

RS-422

Cabling: Single ended

Communication mode: Full duplex, Half duplex

Number of devices: 5 Transmitter, 10 receiver

Max. Data rate: 10 MBPS for 50 feet

Signalling: Balanced

Mark (data 1): 2v min (B>A) to 6v max (B>A)

Max. distance: 4000 feet at 100Kbps

Space (data 0): 2v min to 6v max (A>B)

Output current: 150mA

RS-485

Cabling: Multi-drop

Communication mode: Full duplex, Half duplex

Number of devices: 32 Transmitter, 32 receiver

Max. Data rate: 10 MBPS for 50 feet

Signalling: Balanced

Mark (data 1): 1.5v min (B>A) to 5v max (B>A)

Max. distance: 4000 feet at 100Kbps

Space (data 0): 1.5v min to 5v max (A>B)

Output current: 250mA