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Event Driven Communications

In a typical radio modem system, the master station continuously polls all the remote stations. The polling traffic generates a major overhead with a lot of idle poll and reply messages. System NM solves the overhead traffic issue by using event driven communications. The RTUs communicate with the centralized NM‑CCU only when any status points have changed or a status update is requested by the master. The number of idle polls is reduced to a minimum. The event driven functionality preserves precious radio bandwidth, making the communications more efficient and scalable.

Built-in Repeaters with Redundancy

System NM radio units, RNOs/RNIs, can act as repeaters, passing messages to other radios. The repeating functionality greatly enhances the geographical coverage of System NM radio networks.

The RNI/RNO software option on the PDR 300 allows up to 5 hops, i.e. 6 radios in any one chain, giving the real wide-area coverage that can overcome the problems posed by difficult terrain. The feasible distance between any two radios depends on:

  • the data rate
  • the frequency used
  • the type of antennas
  • the reliability required.

There are working PDR systems in the VHF spectrum communicating over distances of up to 50 km and in the UHF spectrum reaching up to 30 km. A PDR 300 can act as a repeater forwarding data messages to its neighbours to cover an area of several thousand square kilometres.

Having outstanding receiver sensitivity the PDR 300 can communicate over distances not achievable by other wireless devices.

Security & Reliability

All our PDR 300 radios carry unique radio IDs, which means that the wireless data radio system cannot be listened to or interfered with. The PDR 300 also features forward error correction with bit interleaving to bolster its immunity to interference. This enables it to recover data packets with up to 30% corruption.

Radio Flexibility

The radio has a tuning range of up to 70 MHz, allowing users to easily change the frequency within the band and to employ duplex frequencies with a very wide separation. The power output can be set anywhere between one milliwatt and 5 W. The signal strength can also be adjusted to suit noisy environments and the bandwidth can be configured to either 12.5 or 25 kHz.

Data Rates

The PDR 300 has an over-the-air data rate of up to 19.2 kbps.

Versatile Data Interfaces

The PDR 300 has dual RS-232 ports and Ethernet ports. This allows a variety of connections to the central system and the slave devices along with the possibility to mix host systems.

Flexible Setup

Configuration is either via standard terminal software using a serial connection or through an SSH session over Ethernet. The interface has clear built-in menus.

The radios are all identical: there is no need to buy separate base stations, outstations and repeaters. Each PDR 300 can be configured to fit any application. This also reduces the need to store service spares.

Remote Diagnostics

The PDR 300 enables the user to easily perform measurements on their wireless network bit error rate and also run a communication test of the whole system, including alternative communication paths.

Compliant with European Radio Equipment Directive (RED)

The PDR 300 has been certified according to the new European Union Radio Equipment Directive (2014/53/EU).

System NM Software Options

RNI 12: Pure System NM radio

The RNI 12 software communicates with Netcontrol’s System NM devices. It speaks with a central System NM concentrator, the NM CCU, which in turn connects to a SCADA system via a standard protocol such as DNP3 or IEC 60870-5-101.

The RNI 12 software supports event-triggered communication to maximise spectrum efficiency. Each RNI 12 radio can also act as a repeater forwarding messages to other units. Messages can pass through 4 other radios before reaching their destination.

A PDR 300 running the RNI 12 application is backward-compatible with the RNI 12 v1 & v2 and RNI 11 radios.

RNO 401: System NM with Tunnelled DNP3

The RNO 401 software is used to create a protocol link between the NM‑CCU and each RTU. The NM‑CCU embeds messages from the SCADA into System NM messages and sends them to the addressed RTUs via any configured repeaters. At each outstation the RNO 401 software extracts the DNP3 messages and sends them to the RTU.

RNO 501: System NM with Converted DNP3

The RNO 501 software is designed for connecting a DNP3-protocol RTU/IED to a System NM network. The software communicates continually with the slave DNP3 device and then sends the messages to the NM-CCU using the more efficient System NM method, avoiding the lengthy DNP3 messages on the air. At the NM-CCU, the messages can be converted back to DNP3 or to another SCADA protocol, such as IEC 60870-5-101 and RP570.

This software makes the PDR 300 backward-compatible with the legacy RNO 501 v2 radio.

3rd Party Communications

In addition to private radio, System NM can use other networks as well. Examples are:

  • TETRA
  • Fiberoptic
  • GSM / GPRS / WCDMA