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RS-485
EntityQ1047466· pop 22· linked from 251 articles

Also known as TIA-485(-A), EIA-485

thumb|Texas Instruments VN08 (SN75HVD08) - Wide Supply Range RS-485 Transceiver RS-485, also known as TIA-485(-A) or EIA-485, is a standard, originally introduced in 1983, defining the electrical characteristics of drivers and receivers for use in serial communications systems. Electrical signaling is balanced, and multipoint systems are supported. The standard is jointly published by the Telecommunications Industry Association and Electronic Industries Alliance (TIA/EIA). Digital communications networks implementing the standard can be used effectively over long distances and in electrically

Key facts

Fieldbus protocol.name
TIA-485-A(Revision of EIA-485)
Fieldbus protocol.standard
ANSI/TIA/EIA-485-A-1998 Approved: March 3, 1998 Reaffirmed: December 7, 2012
Fieldbus protocol.physical_media
Balanced interconnecting cable
Fieldbus protocol.network_topology
Point-to-point, multi-dropped, multi-point
Fieldbus protocol.maximum_devices
At least 32 unit loads
Fieldbus protocol.maximum_distance
Not specified
Fieldbus protocol.mode_of_operation
Different receiver levels: binary 1 (OFF)(Voa–Vob binary 0 (ON)(Voa–Vob > +200 mV)
Fieldbus protocol.available_signals
A, B, C
Fieldbus protocol.connector_types
Not specified

via Wikipedia infobox

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Commons category
RS-485
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via Wikidata · CC0

~12 min read

Encyclopedic overview

13 sections
Contents
  • Overview
  • Standard
  • Full duplex operation
  • Converters and repeaters
  • Network topology
  • Protocols
  • Applications
  • Signals
  • Waveform example
  • See also
  • Notes
  • References
  • External links

thumb|Texas Instruments VN08 (SN75HVD08) - Wide Supply Range RS-485 Transceiver RS-485, also known as TIA-485(-A) or EIA-485, is a standard, originally introduced in 1983, defining the electrical characteristics of drivers and receivers for use in serial communications systems. Electrical signaling is balanced, and multipoint systems are supported. The standard is jointly published by the Telecommunications Industry Association and Electronic Industries Alliance (TIA/EIA). Digital communications networks implementing the standard can be used effectively over long distances and in electrically noisy environments. Multiple receivers may be connected to such a network in a linear, multidrop bus. These characteristics make RS-485 useful in industrial control systems and similar applications.

== Overview == RS-485 supports inexpensive local networks and multidrop communications links, using the same differential signaling over twisted pair as RS-422. It is generally accepted that RS-485 can be used with data rates up to 10 Mbit/s or, at lower speeds, distances up to . As a rule of thumb, the speed in bit/s multiplied by the length in meters should not exceed 108. Thus a cable should not signal faster than .

Excerpted from Wikipedia’s “RS-485” article, available under the CC BY-SA 4.0 licence.

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