| RS423 | |
|---|---|
| Standard | EIA RS-423 |
| Protocol information | |
| Physical media | Group of copper cables |
| Network topology | Point-to-point, Multi-dropped |
| Maximum devices | 10 (1 driver & 10 receivers) |
| Maximum distance | 1200 meters (4000 feet) |
| Mode of operation | Single-ended (unbalanced) |
| Maximum baud rate | Up to 100kbit/s |
| Voltage | -6V to +6V (maximum) |
| Mark(1) | -4V to -6V |
| Space(0) | +4V to +6V |
| Available signals | Tx, Rx, GND |
| Connector types | Not specified |
RS-423, also known asTIA/EIA-423, is a technical standard originated by theElectronic Industries Alliance that specifies electrical characteristics of a digital signaling circuit. Although it was originally intended as a successor toRS-232C offering greater cable lengths, it is not widely used.
RS-423 systems can transmit data on cables as long as 1,200 meters (3,900 ft).[dubious –discuss] It is closely related toRS-422, which used the same signaling systems but on a different wiring arrangement: RS-423 differed primarily in that it had a single return pin instead of one for each data pin.[1]
RS-423 specifies anunbalanced (single-ended) interface, similar toRS-232, with a single, unidirectional sending driver, and allowing for up to 10 receivers.[2] It is normally implemented in integrated circuit technology and can also be employed for the interchange of serial binary signals betweenDTE &DCE.
RS-423 is the common short form title ofAmerican National Standards Institute (ANSI) standardANSI/TIA/EIA-423-B Electrical Characteristics of Unbalanced Voltage Digital Interface Circuits and its international equivalentITU-T Recommendation T-REC-V.10,[3] also known asX.26. These technicalstandards specify the electrical characteristics of the unbalanced voltage digital interface circuit.[4] RS-423 provides for data transmission, usingunbalanced orsingle-ended signals, with unidirectional/non-reversible,terminated or non-terminated transmission lines, point to point, or multi-drop.
RS-423 is closely related to theRS-422 standard, both of which use the same overall signaling system, but differ in that RS-422 has a dedicated return line for every data pin, while RS-423 uses a single return line. Use of a common ground is one weakness of RS-423 (andRS-232): if devices are far enough apart or on separate power systems, the ground will degrade between them and communications will fail, resulting in a condition that is difficult to trace.[5]
RS-423 specifies the electrical characteristics of a single unbalanced signal. The standard was written to be referenced by other standards that specify the complete DTE/DCE interface for applications which require a unbalanced voltage circuit to transmit data.[citation needed]
These other standards would define protocols, connectors, pin assignments and functions. Standards such asEIA-530 (DB-25 connector) andEIA-449 (DC-37 connector) use RS-423 electrical signals.[citation needed]
TheBBC Micro computer uses RS-423 with a 5-pinDIN connector.DEC used it extensively with aModified Modular Jack connector. This was sometimes called "DEC-423".[citation needed]
| General | |
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| Standards |
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| Storage |
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| Peripheral | |
| Audio | |
| Portable | |
| Embedded | |
Interfaces are listed by their speed in the (roughly) ascending order, so the interface at the end of each section should be the fastest.  Category | |