Since the private network does not carry public traffic, messages are delivered virtually instantaneously. Furthermore, there are no charges, either for text messages or for internal phone calls between staff using standard mobile phones. Dave Goult, Operations Manager commented, “PMN came and gave us an impressive demonstration of their capabilities onsite. Although we had some initial teething problems, these were ironed out. The solution has delivered on its promise and allowed us to achieve our goal.”
Kemira Water operates four production lines at its Bradford facility, manufacturing polymers used in municipal and industrial water treatment processes. The production lines are, essentially, fully automated and run by a SCADA (Supervisory Control & Data Acquisition) industrial control system. The system raises various alarm states should operator intervention be required. In the event of a serious issue occurring, the control system is quite capable of shutting down a production line automatically.
As the production lines look after themselves most of the time, the company sought a more flexible approach to deploying the staff responsible for responding to any alarm states, freeing them from the confines of the control room to carry out other duties on-site. Naturally, health and safety issues are paramount and any solution had to conform to stringent requirements.
Kemira Bradford’s Operations Manager, Dave Goult, had previously investigated using their existing mobile network operator to carry the text messages. However, this proved expensive, at up to £800 per month, and the sometimes long delay between an alarm being raised by the control system and being received by personnel on the mobile meant the solution was initially deemed unacceptable.
A private mobile network was installed with sufficient BTS (base transceiver station) units to provide full coverage of the site. The PMN solution integrates with the SCADA control system to receive and transmit text messages via SMS and with the company’s normal telephone system, enabling external calls to be made from a mobile phone at the company’s landline tariff when on site. Staff are required to reply to alarm messages within a defined time period, otherwise the alarm notification is cascaded down a predefined list of staff until a response is received.