IEC 61156-7:2023

Overview

IEC 61156-7:2023 - Multicore and symmetrical pair/quad cables for digital communications, Part 7 - is the sectional specification for symmetrical pair cables with transmission characteristics up to 1 200 MHz. It defines construction, electrical, mechanical and environmental requirements for cables having four individually screened (S/FTP) pairs (optionally with a common screen). The standard supports both digital communications and analogue systems (for example video) that may use up to four pairs simultaneously. Edition 2.0 (2023) updates test methods and aligns clauses with IEC 61156-1:2023.

Key topics and technical requirements

The standard addresses practical and testable cable characteristics needed by system developers and manufacturers:

• Cable construction and materials: conductor, insulation, pair element, screening (individual pair screens and optional overall screen), sheath and identification.
• Transmission performance up to 1 200 MHz: velocity of propagation, phase delay and differential delay (skew), attenuation, return loss and characteristic impedance.
• Electromagnetic parameters: transfer impedance of screens, coupling attenuation (replacing screening attenuation), near-end and far-end crosstalk (NEXT, PS NEXT, ACR-F, PS ACR-F), and alien (exogenous) crosstalk.
• Electrical tests: conductor resistance, resistance unbalance, dielectric strength, insulation resistance, mutual capacitance, capacitance unbalance pair-to-ground, resistance of screens, and current-carrying capacity.
• Mechanical and environmental tests: dimensional limits, tensile and elongation tests, crush/impact, bending, thermal ageing, damp heat, UV, water immersion, flame propagation, smoke and halogen gas evaluation.
• Updated test methods: replaces injection-clamp method (IEC 62153-4-2) with the absorbing-clamp method (IEC 61156-4-5) for coupling attenuation and adds the triaxial test method (IEC 62153-4-9) to align with the IEC 61156 series.
• Blank detail specification: includes a template for product specification and procurement.

Applications and users

IEC 61156-7:2023 is relevant to:

• Cable manufacturers designing S/FTP multicore data and analogue video cables.
• System developers and integrators evaluating cable performance for high-speed digital links and multi-pair analogue/video systems.
• Test laboratories and conformity assessors performing transmission and EMC-related measurements (coupling attenuation, transfer impedance, crosstalk).
• Specifiers, procurement teams and installers who need standardized requirements for building and infrastructure cabling up to 1 200 MHz.

Related standards

• IEC 61156-1:2023 (general requirements for multicore and symmetrical cables)
• IEC 61156-4-5 (absorbing clamp method for coupling attenuation)
• IEC 62153-4-9 (triaxial method for coupling attenuation)
• Other parts of the IEC 61156 series covering test procedures and cable types.

Keywords: IEC 61156-7:2023, symmetrical pair cables, S/FTP, 1 200 MHz, coupling attenuation, transfer impedance, crosstalk, multicore cables, digital communications, analogue video.