Communications - RTU Module
MultiSmart supports high speed ethernet and serial communications with open protocols in its RTU module. Open protocols means you are never locked in to one vendor.
DNP3 is the preferred protocol for communicating between the field hardware and a SCADA system.
Modbus is the preferred protocol for local communications in a control panel.
Other protocols can be added to the MultiSmart RTU as future enhancements. Contact us if you would like to see another protocol inside the product.
DNP3
DNP3 is an open and public protocol specifically designed for the requirements of telemetry. It has great flexibility and is widely used in the electricity industry, but the main benefits for the water industry are:
- Date/time stamping - each event and alarm has a native date/time stamp. So if data is received by the SCADA system or historian either minutes or hours later the event is logged as occurring at the original time, not the time when the SCADA received it. This means if a radio failed and was not replaced for several hours, all of the data from that period would still make it to the SCADA and historian - not the case with a protocol like Modbus.
- Different classes of data - for example, you can nominate critical alarms to be sent immediately, and event data (eg pump on/off times and level changes) to be sent every 30 minutes, or when polled by the SCADA system. And because the original date/time is always kept, the SCADA has a perfect record. This kind of arrangement ensures that bandwidth is used effectively, rather than having to send every event as it occurs (as happens with MODBUS protocol).
- Guaranteed delivery - The protocol supports acknowledgements from the SCADA (or other master unit) to ensure that alarms are never lost.
- Supported by many suppliers worldwide - because no manufacturer owns it, the customers don't get locked in to one supplier, giving customers peace of mind and a better choice of equipment.
Secure communications - read the white paper about DNP3 security. You can also visit the DNP3 users group website - www.dnp3.org
Why use DNP3 for telemetry? Read the white paper on why DNP3 is the preferred protocol for telemetry.
Or read some of the MultiTrode Blog posts on DNP3 communications.
You can view the MultiSmart DNP3 Compliance Certificate and Report in the Product Manuals section.
Radio, cellular and phone lines
The MultiSmart RTU module supports a variety of communications methods as well as redundant communications:
- Radio over RS232
- Radio over ethernet
- Cellular data
- Cellular voice
- PSTN (phone lines)
It does this by support for RS232, TCP/IP, UDP/IP and a sophisticated modem handler (PPPM = point to point protocol manager).
The RTU supports full redundancy in communications allowing, for example:
- Radio with cellular modem backup
- Radio with phone line backup
The redundancy can be in polled communications and in unsolicited communications.
Easy SCADA integration
MultiSmart has formed a strategic partnership with Software Toolbox to allow easy integration of MultiSmart via its DNP3 RTU into any SCADA system. 
The TOPServer allows a system integrator to easily bring the wealth of MultiSmart pump station manager data into their SCADA platform.
Browsing data via OPC means that rather than working through the extensive DNP3 points list, the System Integrator or end-user can simply browse the OPC tag list and find the data that is needed.
Level values from lift stations and pump stations - available in the customer scaled values, like ft or metres as well as %
Flow data available per pump - the DNP3 RTU combined with the OPC Server provides easy visibility as to all the available data
Pump efficiency allows the utility to find the assets which are inefficient and replace or service them. Longer term this capability also allows the utility to identify the best pump suppliers for the application.
The MultiSmart Pump Station Manager has a large number of different pump and station faults - allowing water and wastewater utilities to run operations more smoothly and to determine the best place for capital and maintenance spending. The DNP3 RTU in conjunction with the OPC server makes the wealth of data easy to sort through.
Pump and alarm setpoints can easily be changed
OPC
OPC is the most widely used open protocol in the SCADA industry. OPC allows different vendor products to communicate with each other without needing to write drivers from one product to another.
One of the best features of OPC is the way an OPC server "publishes" tags to the network, so an OPC client can view the tags in a Windows Explorer style hierarchy, rather than having to know the obscure naming convention for the tags from that manufacturer.
For more information see the website for the OPC foundation, www.opcfoundation.org
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