Electricity and Control July 2021

CONTROL SYSTEMS + AUTOMATION

The VIP I/O marshalling system comprises a base element,

At a glance  The basic structure of signal marshalling in process automation has not changed in a number of years, although it can cause cost overruns and time delays.  System operators have been calling for planners and suppliers to allow more system flexibility, design independence and a greater focus on key design decisions.  Universal I/O systems meet most of these requirements, but the same flexibility is needed at the interface and marshalling levels.

IOA function modules, and the system cabling connection.

via connectors. The second block is the Input-Output Accessory (IOA) that performs the actual interface function. The third component is a system cable that connects the base element to the I/O system. With this configuration, the requirements of the end user can also be satisfied at the interface and marshalling level. The base element suitable for the I/O system can be installed in the project early on, without the precise signal types having to be defined. The function is then defined later simply by connecting the re- spective function module (IOA), with noth- ing needing to be changed in the wiring. This also means the wiring does not need to be checked again.

example, there is no need to have a detailed breakdown of the types of signals required in each part of the system in order to finalise the electrical design, including the necessary hardware. Universal I/O systems also solve the final requirement, because in this constellation, the detailed engineering can be finalised late in the process. Initially, only basic design decisions are necessary, such as which systems are to be used and what the concept for functional safety and electrical explosion protection should be. Despite all these advantages, universal I/O systems do not fully satisfy the operators’ requirements. Limitations come into play when considering the necessary interface technology. Until now, this was not taken into consideration, even though it is an elementary part of every system. As an example, relays for signal conditioning are necessary on the I/Os configured as digital outputs so that the actuators can be operated with a nominal voltage of 230 V. In addition, system parts used in applications where explosive atmospheres exist or can arise often necessitate interface blocks with intrinsic safety type protection. Other examples include signal isolators for separating ground loops and suppressing signal distortions and a range of other functions. Interface functions can be defined later It is important that the necessary interface technology is also considered. If operators use conventional solutions, such as interface blocks mounted on a DIN rail, the advantages gained from the universal approach are almost completely lost. The reason is clear: selecting the interface components means the precise type of signal must be known early on. Moreover, signals would need to be marshalled again in order to wire the field signals to the individual function blocks, such as digital output signals to relays. Therefore, solutions that provide the same flexibility at the interface and marshalling levels as universal I/O systems provide at the I/O level are required. The VIP I/O marshalling system from Phoenix Contact offers a solution. VIP I/O marshalling is a portfolio designed for use in uni- versal I/O systems. In essence, it comprises three blocks. The first of these is a base element that is attached to the DIN rail. The base element accommodates the field wiring and provides the connection to the I/O system

The intelligence is moving closer to the process in the field; universal remote cabinets are a compact and standardised solution for this.

Decentral control box solutions from a single source The universal I/O approach breaks open the mold of the rigid marshalling, interface, and I/O level structures. The intelligence is now moving closer to the process in the field. Universal remote cabinets have become established as a compact and standardised concept for this purpose. Following the principle of ‘We connect the field to your control system’, Phoenix Contact provides a comprehensive range of products and solutions for automation in process technology and process engineering applications. In addition to the flexible I/O marshalling system, various other products and services are available, in particular for decentral control boxes with universal I/O systems. These include power supply units that satisfy the specific environmental demands, surge protection products, terminal blocks, and Industrial Ethernet components. With its tailor-made solutions based on a future-oriented product range, Phoenix Contact has established itself globally as a reliable partner for the process industry. In summary, the VIP I/O marshalling portfolio includes both 8- and 16-channel base elements for various I/O systems. A broad range of function modules – for example, feed-through terminal blocks, fuse modules, analogue isolators also suitable for Ex areas, relay modules, and safety relays – provides the right interface for almost any demand. □

For more information visit: www.phoenixcontact.com

Electricity + Control JULY 2021

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