March 2017

In response to customer requests, Halytech has implemented the Distributed Network Protocol (DNP3) for its microSpider2 and hydrospider2 data loggers.

DNP3 is a standard protocol commonly used in the utility and water resource industries to integrate remote sensors and controllers into a central SCADA (supervisory control and data aquisition) system.

The microSpider2 or hydrospider2 acts as a DNP3 outstation, or RTU (remote terminal unit), and is monitored and can be controlled by the SCADA operator's console.  In a SCADA environment, the operator has an integrated view of data and alarms from outstations across the network, and can operate controls on any connected outstation.

The DNP3 implementation complies with Level 2 of the DNP3 standard.  Every input, including digital switch, counter, analog, Modbus and SDI-12 types, can be monitored and every control can be operated by the SCADA system.  All DNP3 level 2 operations are supported, including counter freeze and clear and outstation reset.  See the device profile document for details.

DNP3 is designed for efficient use of communications channels, where the outstation sends data only as needed, and the microSpider2 or hydrospider2 fits perfectly into this communications model.

When connected by Ethernet LAN (local area network), as might be appropriate for a microSpider2 Industrial in an industrial setting, the unit can remain connected to the DNP3 master at all times, sending updates whenever an input changes and immediately responding to DNP3 requests or commands.

More often, the units are installed in remote locations and communicate via 3G modem.  The unit can be configured to connect to the master station only when it has new data to report, which could be when an alarm is activated and/or on a periodic basis.  For example, the unit could connect to the DNP3 master whenever an input, such as water level, goes above a critical level, allowing the SCADA operator to become immediately aware of the alarm condition.  In addition, the unit could connect once or twice a day (or hourly if you prefer) to send any less-critical data logged since the last transmission and respond to pending DNP3 requests.

No special SIM is needed for this operating mode, making it practical to use DNP3 with any microSpider2 or hydrospider2 via 3G modem.

DNP3 can be used alongside the existing reporting and alarm facilities, including email, FTP and SMS.  You could, for example, periodically send data via DNP3 to a SCADA system, and send a daily report via email, and send both DNP3 data and an SMS message when an alarm becomes active.  Or just use DNP3 for everything - the mix is entirely up to the user.

For those customers who already have microSpider2 or hydrospider2 units installed and wish to integrate them into their SCADA system, the software can be upgraded to include the new DNP3 option.