ARF868 Radio Modems - User guide version V1.8.1
13
Page
of 26
2.3. Radio specifications
2.3.1 Introduction to the radio requirements
The modems use the European frequency band 863-870MHz. This frequency band is segmented into different sub-bands each with their own
regulatory requirements both in terms of power, spectral bandwidth, and use of the spectrum. ARF868 modems accept these regulatory require-
ments.
2.3.1.1
Sub-bands
Each sub-band is defined by a minimum and maximum frequency. In addition, the maximum authorised power and the maximum Duty Cycle are
defined separately for each sub-band.
2.3.1.2
Duty Cycle
The purpose of the Duty Cycle ratio is to make sure that no application can occupy a frequency band for more than a certain percentage of the
time. The duty cycle defines a maximum percentage of time (expressed in percentages of any period of hours during which a modem is autho-
rised to transmit. The limitation of the duty cycle should be monitored by the terminal equipment connected to the modem. Please contact Adeu-
nis RF for your calculations of your “air” occupation time.
2.3.1.3
Schematic representation of the requirements of the 863-870MHz frequency band
The table below is a schematic representation of the use of the 863-870MHz frequency band as used by the Adeunis RF ARF868 model.
Power (mW)
500
25
10
5
SRD
SRD
SRD
SRD
SRD
0.1%
1%
10%
10%
100%
870
869,7
869,65
869,4
869,3
869,2
868.7
868.6
863.05
SRD
0.1%
Caution: this table is non-contractual and is subject to changes in regulations.
2.3.2 ARF868 modem operating modes
ARF868 modems have two operating modes:
•
1
standard mode
dedicated to very long ranges and for which immunity to jammers is optimum.
•
1
ARFx3Pro
mode which ensures “air” compatibility with the whole of the Adeunis RF ARFx3Pro modem range.
The default communication mode is the standard mode. As soon as it is switched on the modem is capable of transmitting and receiving data
with the parameters in its memory (*).
By default, the modem is in permanent listening mode of the RF interface and the UART port.
•
As soon as a frame from the RF link is demodulated, its content is transmitted to the UART port
•
As soon as a character chain is detected on the UART port, it is transmitted to the RF link.
(*): On first switching on the parameters are the default parameters (or factory settings). At subsequent switchings on the parameters used are
those last memorised with the AT&W command (see § 5.2 AT Commands).
SRD
: Short Range
Devices
