Overview
ISO 23570-2:2005 specifies a hybrid communication bus for distributed installations in industrial automation - primarily machine tools and large automation equipment. The standard defines the physical interconnection of sensors, actuators and I/O modules to a shared hybrid bus that carries both fieldbus communications and low-voltage power. Its goal is to reduce wiring complexity, simplify maintenance and support modular replacement of elements in complex machine systems.
Key topics and technical requirements
- Hybrid cable formats: Two approaches are supported - fibre-optic (POF) based and twisted-pair based communication channels.
- Fibre-optic cables: Each cable contains two POF waveguides (transmit and receive) compliant with IEC 60793-2-40 (A4 multimode) and 4 copper conductors (cross-sectional area 1.5–2.5 mm²). Cable sheath colour for fibre-based hybrid cables is violet; sheath must resist industrial lubricants and coolants.
- Connector and contact assignments: Connectors are polarized to avoid incorrect mating. Copper contacts must support ≥ 5 A per contact. Contact mapping (fibre option) defines two independent 24 V DC power circuits (Power supply A unswitched and Power supply B switched) with specified contact assignments for +24 V and 0 V.
- Network topology: Designed for daisy-chained multi-drop topologies; star topologies are outside scope. Each network unit (module) uses two connectors - upstream and downstream - to maintain the daisy chain. Removable modules may be implemented but specific methods are out of scope.
- Environmental & identification: Components shall meet IP65/IP67 (IEC 60529). Default low-voltage cable sheath colour is grey unless otherwise specified.
- Diagnostics & modularity: The standard includes connector pinouts and diagnostic functions appropriate to sensors and actuators to facilitate maintenance and quick replacement.
Applications and users
- Machine tool OEMs and system integrators implementing distributed I/O and sensor/actuator networks
- Cable and connector manufacturers designing hybrid assemblies (POF + power) and M12-style connectors
- Maintenance engineers and plant electricians seeking standardized wiring, color-coding and connector assignments to reduce spare-part inventories and downtime
- Control-system architects specifying fieldbus cabling that also supplies auxiliary low-voltage power
Related standards (referenced)
Adopting ISO 23570-2:2005 helps standardize hybrid communication bus cabling and connectors, improving maintainability and lowering lifecycle costs for complex industrial automation systems.