The Internet is ubiquitous, but will it be there when you need it?
Voice callout of alarms over standard dial-out telephone technology is preferred solution, some say
Managers of municipal water and wastewater facilities that are often unmanned and in remote locations rely on monitoring and alarm systems for prompt notification of troubling events, from low tank levels to sewer pump overflows. With the proliferation of mobile devices, there are several notification options from which users can choose.
Alarm notification can be by messaging using e-mail or cell-phone text, for delivery to PCs, laptops, tablets or smart devices. Reliable Internet access is required, and this can be a problem in some remote areas. Giving employees Internet access and smart devices has its own set of issues.
“Municipal water and wastewater facilities are cautious customers,” says Mack McGhee, president of Sunapsys, Inc., a Vinton, Va.-based company that engineers and implements supervisory control and data acquisition (SCADA) systems for municipalities. “Some of them avoid connecting their systems to the Internet for security reasons. In those cases using voice callout of alarms over standard dial-out telephone technology is the preferred solution.”
Supervisory control interface
“Most SCADA systems and alarm programs don’t offer this notification option,” says McGhee. Even when SCADA system vendors recognize the need, voice callout can be a technical challenge. Users will often want customized callout messages requiring text-to-speech conversion of alarm messages. In addition, voice callout requires an internal or external callout device to interface with the phone system.
Sunapsys turns to the EXELE TopView alarm monitoring and notification software to provide a solution for these cautious customers. “TopView is cost effective, easy to implement and marries nicely with the controlling SCADA systems,” McGhee says.
By supporting popular standards such as OPC and SQL, TopView can interface to most SCADA systems on the market today, allowing users to monitor, alarm and send notifications based on measured parameters and alarms from one or more SCADA systems.
Conformance to the OPC connectivity standard is available for most PLCs, SCADA and other type control systems, as well as for data historians. TopView SQL supports ODBC or OLEDB data sources. These are standard interfaces for querying data from databases.
“We use TopView SQL to monitor alarm tables in the SCADA system’s ODBC database,” McGhee says.
No more nuisance alarms
To minimize the possibility of nuisance alarms, the software allows use of time-delay and time-average values. Users can set up multiple conditions, create custom alarm messages with embedded real-time data values and add instructions useful to operators in locating and diagnosing alarms.
There are two options for dial-up notification; modem notification utilizes TAP protocol for pagers and cell phones, while voice notification delivers audible WAV file or text-to-speech alarms as well as keypad acknowledgment of alarms.
“To ensure messages are received and responded to,” McGhee says, “we have set up a cascading queue of alarm recipients, so that if one person doesn’t respond, the next person on the list gets the callout alert.”
Alarm notification using voice communication is a reliable, cost-effective alternative to Internet-based options. Dial-out solutions eliminate the need to provide Web-based or smart-phone technology to everyone on staff. Remote locations, where Internet access is unavailable or unreliable, can use voice communication for a robust, cost-effective option that is configurable and simple to implement.
EXELE Information Systems, Inc. is a consulting and software engineering company founded in 1978 specializing in manufacturing applications and process control. Sunapsys, Inc. specializes in design and implementation of controls and information systems for municipalities, manufacturers and OEMs. www.exele.com