RS-530, EIA-530 (RS530, EIA530, RS422 signaling) Connector / Signaling Standard
An explanation of the standard, its characteristics including pinouts and how the interface is generally used in practice.
Interface Standards
RS-530 (often written as RS530) is a specification for a differential communications interface that uses a DB-25 connector and differential equivalents of the V.24 (RS-232) signals. The majority of the singalles conform to the RS422 standard and for the majority of requirements requiring RS422 signalling the RS530 cable is suitable. Some of the link management controls signals are implemented using V.10 (RS-423) single ended interfaces, and a variant of this standard called RS-530A / EIA-530A also uses V.10 for the DTR signal. Note that the EIA standards have effectively replaced the RS standards.
Interface Characteristics
RS-530 is a differential communications interface with some single-ended link management signals, typically limited to a maximum throughput of 10Mbps. Communications over distances exceeding 1000m is possible at low bit rates, the actual performance being mostly dependent on cable specification. Separate clock lines are used for receiving and transmitting data.
Interface Applications
EIA530 interfaces are commonly found on communications equipment in some parts of the world where high throughput and/or long distances are required. The interface also offers good noise immunity enabling reliable communications in environments where there are high levels of EMI (electromagnetic interference).
Applications include high-speed connections between satellite modems and host computer systems.
Interface Connector Types and Pinouts
The signals used by the overwhelming majority of applications are marked in bold.
|
DB25 Connector Pinouts |
||
|
Signal Name |
DB25 Contact |
Supported on FarSync cards |
|
Shield |
1 |
Yes |
|
Transmit Data (A) |
2 |
Yes |
|
Receive Data (A) |
3 |
Yes |
|
Request To Send (A) |
4 |
Yes |
|
Clear To Send (A) |
5 |
Yes |
|
DCE Ready (A) |
6 |
|
|
Signal Ground |
7 |
Yes |
|
Receive Line Signal Detector (A) |
8 |
|
|
Receive Signal Element Timing (B) |
9 |
Yes, see Note |
|
Receive Line Signal Detector (B) |
10 |
|
|
Ext. TX Signal Element Timing (B) |
11 |
|
|
Transmit Signal Element Timing (B) |
12 |
Yes |
|
Clear To Send (B) |
13 |
Yes |
|
Transmit Data (B) |
14 |
Yes |
|
Transmit Signal Element Timing (A) |
15 |
Yes |
|
Receive Data (B) |
16 |
Yes |
|
Receive Signal Element Timing (A) |
17 |
Yes, see Note |
|
Local Loopback |
18 |
|
|
Request To Send (B) |
19 |
Yes |
|
DTE Ready (A) |
20 |
|
|
Remote Loopback |
21 |
|
|
DCE Ready (B) |
22 |
|
|
DTE Ready (B) |
23 |
|
|
Ext. TX Signal Element Timing (A) |
24 |
|
|
Test Mode |
25 |
|
The RS50, EIA530 standard is supported on the FarSync range of communications products
Note: FarSite specifies the use of a cable with the DCE supplying both Transmit and Receive clocks with identical frequency and phase direct to a FarSync card or alternatively via a suitable conversion cable to a FarSync X.21 cable.
Information in this document is subject to change without notice.
Other products and companies referred to herein are trademarks or registered trademarks of their respective companies or mark holders.
Last updated: 28 May 2004
