ASCOT AUTOCLAVES
Autoclaves, Sterilizers, Washer disinfectors, flexible endoscope washers, validation to HTM2010, HTM2030, and HTM2031.

Omron Press Release

The UK's first use of the SMC pneumatics valve island, configured for use with Omron's Compobus/S fieldbus will be by Ascot Autoclaves, a small but dynamic supplier of medical equipment.

To date Ascot has built its reputation on refurbishment and re-engineering of large steam sterilizing autoclaves used in hospitals, pharmaceutical laboratories and similar medical/life science facilities. But it is now to launch its own product, using a design bristling with technological innovations.

We are big fans of the fieldbus control," says Robert Warren, founder and MD of Ascot. "It reduces our wiring and commissioning times by a considerable margin and gives us the freedom to distribute the control equipment around the autoclave."

Warren therefore decided to use a fieldbus on the machine he was designing, and commensurate with this he was also keen to employ a pre-wired pilot valve island to control the big steam valves that are the operational heart of the autoclave. It was recognised that Omron's Compobus/S fieldbus would be the optimum choice of protocol because it is so good, not only at handling digital I/O, but also analogue values like temperature and pressure measurements.

" I was delighted with this advice, because I use Omron control equipment almost exclusively, preferring it and the back up support over other suppliers," says Warren. "In fact an Omron touchsreen NT31 is to be our new autoclaves most visible innovation and a lead selling point."

He explains that autoclaves are fairly complex pieces of equipment with a detailed operational cycle. Typically, a rack full of medical equipment is wheeled in and the motorised door is locked and interlocked. The chamber is then evacuated to a specified vacuum pulses followed by an extended steam sterilising period and finally a drying vacuum.

All this is controlled from a single touch screen, programmed with a series of graphic displays and text prompts. " Showing people how to use autoclaves fitted with an Omron touchscreen is usually a fairly relaxed 15 minute job, compared with an intensive days training with conventional controls," he enthuses.

Another innovation Ascot is incorporating on its groundbreaking new autoclave design is based on the Omron CS1 programmable logic controller(PLC). This has the ability to record large amounts of data straight onto a flash memory card, so the autoclave operators can build up a comprehensive archive of every detail of every operation the unit performs, a level of record keeping that is becoming almost routine in medical circles.
The CS1 can also be used to drive a conventional paper printer for operators who prefer a more traditional method of record keeping. On its refurbishment work Ascot has tended to use Omron C200HX PLC to date. The new CS1 was designed to allow importing of existing C200HX programmes with minimal modifications required to upgrade from one controller to the next.

Warren is using a single PLC to control all the autoclave functions and monitor process values, in conjunction with Compobus/S I/O units, Compobus/S analogue I/O units, Omron power supply, motor control gear and safety relays.

" Most autoclaves are designed for a ten year working life, and many are rebuilt to double this," observes Warren. "Much of our refurbishment work involves replacing dated bespoke control systems with a central PLC, the reliability gained being a significant advance for the user. So when they see all the new control concepts incorporated into our machine, most are stunned by what we are achieving.

Issued By Bob Dobson.