Continuous pressure to reduce costs and growing system complexity in process engineering requires new automation concepts. Automation firm Phoenix Contact presents the innovative Process Interface. Considerable cost reductions with parallel wiring or large signal quantities can be realised with installation concepts which enable a compact design of the marshalling and interface levels.
In the following, an innovative concept will be presented in the form of the Process Interface from Phoenix Contact, which takes these requirements into account, considerably reducing engineering and installation effort and expense while simultaneously offering the greatest possible flexibility and safety.
In addition, this concept also offers uniform system solutions from one supplier, consisting of connection technology, wiring, interface and over voltage protection components for the entire signal path between the field device and the control system.
A typical design for process control engineering of chemical and petrochemical systems is shown above right.
The connecting cables of the measuring transducers, actuators and solenoid valves located in large numbers and in varying density in the field are initially presorted and combined in the local field distributors.
From there multi-core cables carry the signals from the Ex area into the marshalling level of the switching and control building, where the field cables are connected to input terminal blocks (often with knife disconnection).
With multi-core master cables, the respective measuring variables then flow into the interface level, on which signal conditioning (Ex/non-Ex isolation and signal adaptation) is carried out.
Now it continues to the supervision level either directly or via other distributors.
As a specialist for connection and interface technology, Phoenix Contact has developed a concept especially for the control room area of the process engineering with the Process Interface product line, which considerably reduces the space requirement and the installation effort expense with simultaneous demanding requirements with regard to system availability (including with single-loop integrity), short commissioning times, clear layouts and maintenance friendliness.
Consistently compact and service-friendly with 12.4mm
The design on the Process Interface is based on the development of pluggable, intrinsically safe interface modules just 12.4mm wide and a uniform base for use on mounting rails, also with a width of just 12.4mm and the connection convenience and safety of a perfected modular terminal block.
This small width was enabled partially by the use of patented, flat Ex-I isolating transformers and SMD circuits with a low power loss. With a width of 12.4mm, the Process Interface takes up no more space per loop in the mounting rail than common marshalling terminal blocks.
The base or the Process Interface base terminal block is equipped with test sockets for each cable toward the field, which are located in front of and behind the integrated disconnection knife.
The knife disconnection allows fast, safe disconnection of the signal path when performing service. However, for diagnostic purposes a measuring device can also be coupled to the current loop without interrupting the circuit.
Space through integration
In addition to the very small width, this concept also offers the user the advantage of being able to install and pre-wire the Process Interface base terminal block directly in the input strip of the marshalling distributor.
The power supply can be connected quickly and safely here with insertion bridges without additional wiring effort and expense. The functional adaptation during commissioning is carried out by connecting the respective interface modules, which engage self-coding and are vibration-proof.
Depending on the individual application, marshalling can now be carried out Ex-free either on modular terminal blocks or on a wide range of available Varioface interface modules, which produce an inexpensive, safe connection to the various controllers via system wiring.
With this combination of the marshalling and interface levels, the required switch cabinet space is again considerably reduced.
Complete product range
For the various tasks of process engineering, the Process Interface product line from Phoenix Contact offers the user intrinsically safe, Smart-capable measuring-transformer supply units, Namur switching amplifiers, valve control modules, buffer amplifiers and programmable temperature measuring transducers for resistance thermometers and thermal elements.
Non-Ex versions are also available. Some features common to all devices are the three-way electrical isolation, the low power loss and exact signal processing.
All devices are equipped with status displays, single-loop integrity to increase the system availability and are compatible to most field devices. The Namur switching amplifiers have a phase reversal option so that the output always assumes the safe state in case of a fault.
Universal components with a future
The intrinsically safe Process Interface components are approved as related operating equipment for all zones and gases with the code [Eex ia] II C and certified in accordance with the guideline ATEX 100 a binding from 07/01/2003.
The Process Interface, with its unique functions and its economy, is already in use in refineries, in the chemical industry, on drilling platforms and oil tankers, and contributes to high system availability.
