Technologies / Control systems

NIS have a vast array of control system experience gained throughout our diverse market sectors. As system integrators we are adept at matching existing systems to new, state of the art control systems. We offer a full in-house service from concept design to panel build, including simulation, works testing, installation and commissioning.

Our engineers have worked with many control system types, including:- 

Programmable Logic Controller (PLC)
Over the last 20 years PLCs have replaced the discrete panel components and relay logic of older systems. This has allowed panels to be compact, the wiring time/cost to be reduced, and changes to control systems became easier to implement. A diagrammatical method of programming PLCs (known as ladder logic) has also been developed, as an evolution from the simple statement commands of the past. Initially a PLC could only handle simple digital inputs and outputs, but can now handle a wide range including analogue, thermocouple, RTD, encoders etc. Processing speed has also reduced to around 10 microseconds as the technology has evolved.

Distributed input/output (I/O)
Further developments in PLC systems have been to take the I/O from out of the electrical panel and put them closer to the device. The advantage is that it is possible to observe status indications on the I/O devices, from a local position. Also, many PLC manufactures have developed ‘gateways’ that make it possible to connect almost any third-party device to a PLC system. Other developments in this technology include emergency systems which are now proven and can be used on a network. Additionally, it is now possible to connect a laptop virtually anywhere within the system (even wirelessly) and monitor or interrogate the controls. Other components such as drive systems, weighing systems and vision systems have become ‘intelligent’. This allows these devices to connect to the network and be seen as nodes, or be mounted in the field. The use of this technology has again reduced the size of panels and the manufacture time.

Human-machine interface (HMI) / Supervisory Control And Data Acquisition (SCADA)
As PLCs have developed so have HMIs, and it has become possible to reduce the number of pushbuttons and indicating lamps on panels; and to include operator prompts, and diagnostic information. There are now full colour touch screen versions that allow graphical representation of the plant, trending, recipes, history, etc. It is also possible to use the HMI as a local panel, allowing changes to process at a local level or for maintenance purposes. On large machines it is typical to have more than one HMI installed.

For bigger systems a PC based system that allows SCADA to be used is available which can communicate with factory management, allowing processes to be monitored and changed remotely (e.g. manager’s office).

Vision Systems
Vision systems are normally used for inspection purposes. This takes out the requirement for an operator, and lends itself to automated processes. In other applications a vision system can be used to determine whether a product is orientated correctly to allow a process to continue, which can then trigger manipulation systems to make adjustments.

Technologies applied have included:

  • Closed loop speed control
  • Distributed I/O ASI, & Profibus
  • Scada, siemens WINCC
  • PLC, Siemens S7-400
  • Wireless network for maintenance functions
  • RF identification
  • Weighing
  • PLC Mitsubishi Q series
  • Distributed I/O, ASI
  • Robots, Motoman
  • Inspection, Keyance
  • HMI, Proface
  • Profibus
  • Profinet
  • PLC Siemens S7-400
  • SCADA WINCC
  • CCTV Bosch