Slaves for single column applications

Paul Boughton

Siemens Automation and Drives is launching a new generation of Sirius 8WD44 AS-i slaves for signal column applications.

Developed and designed in response to extensive customer research, the new devices are said to offer users a greater level of functionality than any other AS-i slave currently available.

Using the 8WD44 modular range of 70 mm signal columns, it is possible for customers to combine light elements from a wide range of colours and signalling functions.

Operators can therefore see the exact status of a machine or process from a considerable distance away. With industrial controls spread over such a large area, low-level communications networks like AS-i allow system integrators to significantly reduce cabling between command and signalling locations.

Many existing AS-i installations run version 2.0 – which can link up to thirty-one four-input, four-output (4I4O) slaves.

The ‘standard’ system is served by the 8WD4428-0BE module - which allows up to four light elements to be driven from a single address.

However, increasingly installations specify AS-i version 2.1. The ability to link up to sixty-two 4I30 slaves on a single master has considerable appeal given today’s increasingly complex processes. This so-called ‘A/B’ system is served by the 8WD4428-0BD module. Up to three light elements can be driven from a single A/B address (equivalent to half a standard AS-i address). The introduction of the A/B slave therefore gives system integrators far better value for money than in previous years, as they can install twice as many stacks as before without needing additional masters.

Other improvements include: an integrated internal auxiliary power switch, so only one slave type is required, irrespective of whether the current drain of the complete stack requires an auxiliary 24V supply or not, hence easier selection and reduced stock holding; LEDs visible from the side of the modules show the AS-i system status, allowing for easier diagnostics and maintenance; and an integrated addressing jack that helps towards a more convenient commissioning process. 

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