Overview
ISO 23570-1:2005 - part of the ISO 23570 series on Industrial automation systems and integration - Distributed installation in industrial applications - defines how sensors and actuators interconnect in machine tools and similar large industrial automation equipment. The standard sets clear requirements for M12×1 connectors, 24 Vdc power interfaces, cable assemblies and sheath colours, and basic diagnostic signalling to reduce wiring complexity, simplify maintenance and lower spare-parts inventories.
Key topics and technical requirements
- Protection rating: All specified components shall meet IP65 and IP67 (IEC 60529).
- Connectors: Use M12×1 circular connectors (IEC 61076-2-101).
- Female connectors: 5-contact mandatory.
- Male connectors: 4-contact may be used because contact 5 is unused in this part.
- Cable assemblies:
- Four-wire cables, conductor cross-section 0.34 mm².
- Standard lengths: 0.3 m, 0.6 m, 1.0 m, 1.6 m, 2.0 m (others optional).
- Permitted connector styles for these assemblies: LM, LF, MM, MF per IEC 61076-2-101.
- Sheath colours: shielded = green, unshielded = yellow; other low-voltage control cables = grey.
- No status indicators (e.g., LEDs) allowed on cable assemblies.
- Power and signalling:
- Reference to 24 Vdc supply (detailed power requirements in ISO 23570-2).
- Analogue sensor/actuator channels use 4–20 mA for process signals.
- Digital channels: outputs may be switch closures (0 Ω) or nominal 24 Vdc logic.
- Contact assignments (summary):
- Contact 1 = +24 Vdc; Contact 2 = analogue output / diagnostic (digital); Contact 3 = 0 V; Contact 4 = analogue/digital signal; Contact 5 = unused.
- Diagnostics & indicators:
- Digital sensors/actuators must provide diagnostics on contact 2 (normal = +24 Vdc).
- Sensors/actuators include a yellow LED; I/O modules provide a yellow LED and a bi‑colour yellow/red LED per channel.
- I/O modules:
- Provide female M12×1 connectors and supply 24 Vdc to devices.
- Interface signals via solid-state circuits (not relays).
- Scope limits: The standard does not cover safety operation of equipment or large power devices (e.g., spindle motors).
Applications and who uses it
ISO 23570-1 is intended for:
- Machine tool OEMs and designers implementing distributed installation topologies.
- Automation system integrators standardizing sensor and actuator interfaces.
- Manufacturers of sensors, actuators, cable assemblies and I/O modules claiming conformance.
- Maintenance engineers and plant managers seeking reduced downtime and simplified spare-parts logistics.
Common use cases: modular machine tool cells, distributed I/O racks, retrofit projects standardizing field wiring, and supplier product specifications for industrial sensors and actuators.
Related standards
Keywords: ISO 23570-1:2005, industrial automation, sensors and actuators, M12×1, 24 Vdc, IP65, IP67, cable assemblies, distributed installation, diagnostic functions, I/O modules.