3
Introduction
Cell-Sky-Link-RS485-3G is a base station for 2.4 GHz and 433.92MHz Nokeval-transmitters and part of
Nokeval Sky and Ovazone product families. It receives and buffers radio packets to its non-volatile
memory and transmits them over GSM mobile data networks to Ovaport network service, thus enabling
reliable remote data acquisition from the field straight to the Ovaport servers located in a data center.
Serial interface
The base station can be connected to standard Modbus RTU transmitters and to
Nokeval devices with
SCL protocol
using the integrated RS485 bus. The base station’s reliability is increased by the backup
batteries, which enable uninterrupted data acquisition also during external power interruptions.
Sky radio
Nokeval’s third generation Sky radio devices use the Semtech LoRa modulation technique on the 433
MHz ISM band that allows unforeseen wireless range for battery powered transmitters. The protocol
used is defined by Nokeval, called Sky, which means that these devices are not compatible with the
LoRaWAN infrastructure.
The modulation has some parameters to define its operation. With the “maximal” settings, a very long
range can be reached, but at the expense of high battery and radio band consumption. One radio
transmission can last approx. 2 seconds (compared to 20 ms of the Nokeval MTR series). This means
that the number of transmitters within the range must be limited in order to avoid collisions and to
allow radio time for each. It is not practical to use a short interval between transmissions; 10 to 30
minutes is the recommended interval range.
When the maximal range is not necessary, the parameters should be adjusted for lower battery and
band consumption. All the devices within one network must share the parameters, because the
receiver can only listen with one set of parameters at a time. Consequently, the parameters must be
selected according to the most distant device. It is also possible to adjust the transmission power. The
devices that are closer to the receiver can use a lower power setting.
Before using these 433 MHz radio devices, make sure it is legal in your country.
Ovanet radio
Ovanet is Nokeval’s second generation radio network, which uses Wirepas Pino technology and
Nokeval’s own additions. The network uses 2.4-2.48 GHz band, which is available all over the world. The
product names basically begin with the Ovazone prefix.
Every device in the network, also battery powered ones, will function as a repeater by assisting devices
located far away from the gateway, effectively forming a mesh network.
The network has node devices producing measurement data, and one or more gateways. The gateway
connects the network to other systems. Examples of the gateway devices are Ovazone-Wave-Link and
Ovazone-Cell-Link. They are used to deliver the data of the radio network to the Ovaport service.
Each device, including nodes and gateways, must be set with the same Ovanet network. The Ovanet
network number must be chosen between 1-16777214. It should be generated with a random number
generator to minimize the probability of accidentally choosing the same network number as in another
network located nearby. By default, the devices are set to the network number 6829663, which can be
used if there are no other Ovanet or Wirepas Pino networks within a couple hundred meters range. If
