Bin the wire

Automating a laundry with a control system will enable it to perform at maximum efficiency but, traditionally, the vast amount of obligatory wiring takes a long time to install and test. Today’s modern systems use fieldbus technology to get round this, explains Doug Field, Micross Electronics’ sales and marketing director.

Forward-thinking laundries are specifying control systems based on fieldbus technology. Fieldbus systems offer three main advantages over conventional wiring configurations: they increase the speed of installation; significantly reduce testing times prior to commissioning; and they improve reliability. These advantages ultimately equate to savings on the bottom line.

In a conventional control system, an individual wire is used at every control point. Each of these wires will be run from the control point itself directly to the PC or programmable logic controller (PLC) monitoring the system and, even for a small size laundry, the lengths of wiring involved can total miles.

With a fieldbus system, modules are placed at strategic points around the laundry and act as focal points for anything being controlled or monitored in close proximity. The wiring from solenoids, load cells or other sensors is fed into the module closest to them and a single five core cable then links the individual modules to the computer or PLC.

An important advantage of this system configuration is its potential for rapid on-site testing. The connections between modules and their respective control points can all be tested during assembly before delivery to the laundry. Once on site, the cable from the modules to the computer is the only wiring that needs fitting and testing. This reduces installation times drastically.

An added advantage is that if a fault is detected, it is easy to locate it and simply repair or replace short pieces of wire between a control point and the fieldbus module rather than a whole length running to the computer.

Traditionally, a faulty wire was detected by running a voltage through it and checking the function of the solenoid or load cell at the end of the wire. Today’s technology incorporates self-checking systems that identify the exact position of any faulty wiring allowing it to be rapidly located and repaired. The industry estimates that at least 30% of the time spent wiring and testing conventional systems is saved with a fieldbus system.

The benefits of fieldbus technology are already being enjoyed by other process industries where it is proven and established. Micross Laundry Systems, a company producing monorail control systems since 1984, saw the advantage of applying this technology to laundries and embarked on a major international project to analyse the many types of fieldbus in use across industry.

“We realised that a fresh and innovative approach was required to deliver the full range of benefits fieldbus technology can bring to laundries,” said Nick Nelson, chairman of Micross Laundry Systems. “Our new Tracknet 2000 system offers all of these. It also incorporates other ground breaking technology, our vPLC, to improve laundries’ operating efficiency.

The vPLC, which won a DTI Smart Award earlier this year, is recognised as the latest in processing technology.

“The vPLC is effectively the intelligent part of a traditional PLC that we have designed to plug directly into the motherboard of a personal computer,” explained Nick Nelson. “While the vPLC is still electrically independent, the speed and volume of information that can be processed and communicated to the PC is dramatically improved.

“Now the Tracknet 2000 system can not only control and display the flow of work but can gather, analyse and report data on processes throughout the laundry. This can include water consumption, wash temperatures, the speed of ironers and folders and any other process you desire.” The combination of a vPLC with fieldbus is set to revolutionise control systems in laundries.

“The Tracknet 2000 system is no longer a simple monorail controller,” said Doug Field. “The reduced cost and ease of connecting a wide range of laundry processes to the system through fieldbus modules provides our customers with a comprehensive management information platform that is very affordable.” Other computerised control systems on the market offer a variety of reporting capabilities but often provide too much information in diverse formats and from different sources.

Micross Laundry Systems customises installations to ensure that reported data is relevant and all information comes from a single source. This makes interpretation easy for laundry management.

Johnson Service Group was quick to see the benefits of such a strategy and has installed a Tracknet 2000 system at its Stalbridge Linen Services sites. Installation is also planned at its ApparelMaster UK site in Exeter.