Remote I/O in hazardous areas made simple with Excom

Citation

(2001), "Remote I/O in hazardous areas made simple with Excom", Sensor Review, Vol. 21 No. 2. https://doi.org/10.1108/sr.2001.08721bad.008

Remote I/O in hazardous areas made simple with Excom

Remote I/O in hazardous areas made simple with Excom

Keywords: Sensors, Safety, Hazardous, Handling

Turck Banner introduces Excom, the ultimate, decentralised remote I/O system for use in Zone 1 hazardous areas (see Plate 7).

Excom has been designed specifically to meet the long-established need in the petrochem, chemical, pharmaceutical and offshore sectors for a reliable, remote I/O system that can be installed in Zone 1/Division 1 hazardous areas without the need for additional protection.

Plate 7 Excom from Turck Banner

Until now, major difficulties in developing such a system have included the relatively high energy requirements of analogue intrinsically safe apparatus, which operate with 4-20mA signals, and the need for short cable lengths in the Ex area.

In practice this meant that installations in hazardous areas required small groups of no more than four devices to be wired separately to a flameproof marshalling box and then, via a barrier, to the control device outside the hazardous area. This made them time-consuming, bulky and expensive to install.

Excom's intrinsically safe interface enables a large number of addressable channels to be connected to a single fieldbus cable and mounted together in a compact format, allowing the use of up to 128 digital or 64 analogue channels in the field, even where space is limited.

The result is an inexpensive solution for networking devices at the field level with different control level platforms that will assist system providers to close the gap between the system and the field level in hazardous areas.

With Excom, Turck Banner has produced a modular, rack-based system that allows consistent parameter setting and configuration at the control level (including HART® devices) via a single fieldbus.

Field devices can be connected and power supplies, gateways and I/O modules exchanged online during operation. The option of dual redundancy for the 24V DC or 115/230V AC power supplies and gateways maximises system availability.

IP20 rated modules providing four analogue or eight digital inputs or outputs are mounted on modular racks with a backplane bus, an integrated voltage supply and bus communication. Three standard versions of modular racks can accommodate 18, nine or five modules.

Each backplane is a totally independent, self-contained barrier system with power supplies, gateways, barriers and all connections on board.

Modules are easy to insert and remove via guardrails without the need for additional tools, and use a coding system to avoid interchange errors. They also feature short circuit, wire break, overload and force mode fault indication, with two dual-colour LEDs, providing a visual indication of status and I/O operation.

Modules are addressed using three decimal coded rotary switches that allow up to 200 addresses per bus.

Excom provides an intrinsically safe connection to PROFIBUS-DP with V1 functionality, and the system permits online parameter setting and configuration as well as forcing and substitute value programming for analogue and digital I/Os. Excom also offers an intrinsically safe interface to Zone 0.

The operating temperature range for the Excom system is –20 to +70°C.

With the launch of Excom, Turck Banner has rewritten the rules for remote I/O in hazardous areas. Now cumbersome and expensive parallel I/O can be replaced with a modern, compact, modular bus system, that integrates directly into the installation via industry standard fieldbus connections.

For further information, please contact: George Perkins, Turck Banner Ltd, Stephenson Road, Leigh-on-Sea, Essex SS9 5LS, UK. Tel: 01702 525186; Fax: 01702 420934; E-mail: info@turckbanner.co.uk