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

**URL:** <https://forumautomation.com/t/what-are-the-difference-between-rs-232-rs-422-rs-485/2512>\
**Category:** Industrial Networking\
**Tags:** interviewquestions\
**Created:** [October 25, 2017, 6:05pm UTC](https://forumautomation.com/t/what-are-the-difference-between-rs-232-rs-422-rs-485/2512 "2017-10-25T18:05:25Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![sivaranjith](https://forumautomation.com/letter_avatar_proxy/v4/letter/s/ba9def/32.png) [@sivaranjith](https://forumautomation.com/u/sivaranjith)\
**Post date:** [October 25, 2017, 6:05pm UTC](https://forumautomation.com/t/what-are-the-difference-between-rs-232-rs-422-rs-485/2512/1 "2017-10-25T18:05:26Z")

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> **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