Overview
ISO 2110:1989/Amd 1:1991 is an amendment to the international standard for 25-pole DTE/DCE interface connectors, published by the International Organization for Standardization (ISO). This amendment focuses on updating connector and contact number assignments specifically for DTE/DCE interfaces used in data communication environments where data signalling rates exceed 20,000 bits per second. The amendment ensures reliable, high-speed data transmission and compatibility among equipment designed for enhanced data communication requirements.
This amendment introduces specific changes to clauses and tables in the original ISO 2110:1989 document and adds a new informative Annex B. These updates help data communication equipment manufacturers and integrators maintain consistent connector specifications, improve interoperability, and adapt to advancing technologies.
Key Topics
- Connector and Contact Assignments: Updates to the 25-pole DTE/DCE interface connector ensure clear guidelines for contact numbering in high-speed communication scenarios above 20,000 bit/s.
- Electrical Characteristics: Recommends adherence to CCITT (now ITU-T) Recommendations V.10 and V.11 for electrical features, addressing both unbalanced (V.10) and balanced (V.11) circuits for general use in integrated data communication equipment.
- Interoperability Considerations: Notes on compatibility with existing connectors and devices conforming to earlier or alternative recommendations (such as V.28, V.35, V.36, and V.37) to prevent issues during interconnection.
- Adapter Use and Cross-Reference: Annex B provides informative guidance for interoperation between standards-based equipment, including sample circuit diagrams and compatibility notes for integrating various connector types and legacy devices.
Practical Applications
ISO 2110:1989/Amd 1:1991 is particularly valuable for:
- Network Equipment Manufacturers: Ensuring that routers, modems, switches, and related hardware with DTE/DCE interfaces comply with up-to-date connector assignments for high-speed data transmission.
- System Integrators and Installers: Providing clear reference for implementing or upgrading serial communication interfaces in IT, automation, and telecommunications systems.
- Data Communication Engineers: Facilitating troubleshooting and efficient design of systems that interconnect diverse equipment running at high signalling rates.
- Testing and Maintenance: Supporting accurate identification of contacts and electrical expectations, improving device compatibility, signal integrity, and maintenance operations.
The standard is suitable for applications such as wideband modems, enterprise networking, and other environments where fast and reliable serial communication is essential.
Related Standards
To maximize compatibility and interoperability, this amendment references several related international standards and recommendations, including:
- ISO 2110:1989: The original specification for 25-pole DTE/DCE interface connector and contact assignments.
- CCITT/ITU-T Recommendation V.10: Describes electrical characteristics for unbalanced, double-circuit interchange circuits.
- CCITT/ITU-T Recommendation V.11: Specifies electrical characteristics for balanced, double-circuit interchange circuits.
- CCITT/ITU-T Recommendation V.28: Defines electrical characteristics commonly used with earlier 25-pole connectors.
- CCITT/ITU-T Recommendations V.35, V.36, V.37: Handle specific cases for wideband, high-speed, and legacy modem interconnections.
- ISO 4902 and ISO 2593: Related standards referenced for cross-compatibility and connector assignment mapping.
These references enable organizations to ensure full compliance, minimize errors, and support a robust data communication infrastructure.
Keywords: ISO 2110, DTE/DCE interface, high-speed data communication, 25-pole connector, contact assignment, CCITT V.10, CCITT V.11, data transmission, interoperability, data communication standard, serial communication, network equipment, international standardization.
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