Focus on Savings Potential: The Innovative H-System

Point-to-point connection is the most widely used method of wiring in conventional signal processing. On the basis of a knowledge of the fundamentals of instrumentation techniques and the application of Ohm's Law, signal paths can be interpreted by simple means. The interface module as an isolation level between intrinsically safe field signals and the automation system offers a safe radius of action in established areas:

• An extensive range of galvanically isolated interface modules guarantees precise signal processing
• Easily verified signal paths, even during operation
• Plant extensions can be planned and implemented by skilled personnel, without specialized engineering effort
• Simple demonstration of intrinsic safety using proven methods of representation by means of certificates for the field devices and certificates for the associated EX-i Interface modules
• The application of recognized rules, with due consideration of the hardware, is adequate for the demonstration of functional safety

The answer is simple: For the purpose of plant availability an individual isolation barrier is allocated to every individual field device. Single-loop integrity implies, that in the case of the replacement of a module, only the signal circuit of the one, associated field device is inactive.

With its single-channel interface modules, single-loop integrity is exactly compatible with the multi-channel I/O cards of the control level, because it is known and intended, that the single-channel EX-isolation modules serve as a "firewall" for the field signals before these are passed to the automation system for the control of the processes. Actual practice has shown that the replacement of modules during servicing can even be undertaken by inexperienced plant personnel. Alternatively, the replacement of the I/O cards of a control system has often led to unintended plant downtime.

The termination boards of the H-System are quickly and easily mounted in the safe area or in Zone 2 on a 35 mm DIN rail and are used as the carrier for the galvanically isolated interface modules of the H-System.

Two pairs of terminals on the termination board feed the redundant power supply automatically to each module plug-in position, so that the expensive, manual individual supply of the modules is dispensed with. An additional savings potential of the H-System lies in the use of pre made up trunk cable with multi-pin system connector plugs – the so-called system cables. These simplify the engineering and reduce the expense of the fault-prone individual wiring to the automation system. After function checks on the control cabinet it is no problem to remove the system cable for transport purposes. At the intended location of the system the system cable is simply plugged back in. This significantly reduces commissioning times.

The wiring of the intrinsically safe field devices takes place on blue terminals on the termination board. Termination boards with fixed and removable screw terminals are available, as are spring terminals, to suit your particular operating requirements – the choice is yours!

With the wiring sorted out in this way the interface modules can easily be positioned and snapped in without tools. When servicing is required the signal circuit can be broken during plant operation by simply pulling out the interface module. The wiring remains undisturbed.

Depending on the safety requirements of your system and the space at your disposal, you will always achieve the highest packing density in the control cabinet by utilizing the H-System with termination board technology. You have a choice between compact HiC boards and HiD boards for high signal density in 2 respective versions for a maximum of 8 or optionally 16 interface modules:

• HiC boards for 12.5 mm slim HiC modules with single-loop integrity
• HiD Boards for 18 mm narrow HiD modules with the highest signal density

For service and maintenance convenience, diagnostic messages for power supply and field wiring are available by means of a separate fault warning board.

A HART Multiplexer for communication between the control system and the intelligent field devices can subsequently be fitted at any time.

As standard and without surcharge you receive SIL2/3 certified interface modules and the SIL3 certified HART Multiplexer.

An extensive product range of optional termination boards is available. You benefit from Ex-stock, freely selectable connection technology. Termination boards with system-specific connection technology can be supplied on request.

The HiC and HiD modules offer you the following advantages:

• Simple planning and commissioning with pre-assembled cable
• Fast mounting of the termination boards on the mounting rail
• Less expense on wiring for the power supply
• Less fault elimination, short commissioning times
• No tools used to mount the interface modules
• Codeable plug-in stations
• Simple diagnosis via fault warning board
• Simple HART communication via HART Communication Board
• SIL2/3 included
• International approvals included
• Wide product portfolio

In addition, the slim 12,5 mm HiC modules save over 30 % space with single-loop integrity:

• Dispense with every third control cabinet – and the cost of these
• Reduced power loss reduces costs of power packs and cooling
• Narrow 18 mm HiD modules offer you the highest signal density in the control cabinet.