ML-x17 DATA LOGGER MANUAL
Manufacturers of low power instruments
page 126
5.1.8 +3V6
This is a power output. It is used to power external sensors or a potentiometer. It has a voltage of 3.6 Volts
and is capable of driving up to 100 mA.
5.1.9 Antenna placement and field strength
An antenna is required for 2G/3G/4G and GSM operation. Normally you will require a dual-band antenna
suitable for 900&1800 MHz or 850&1900MHz.
Depending on local field strength the integrated antenna or a simple whip antenna direct connected to the
data logger will work, or a better antenna and/or better antenna placement might be required.
You can monitor the actual field strength through the configuration software(menu). The field strength may
vary on atmospheric conditions, so we recommend you to make sure that the indication is maximized at
installation
The field strength may also vary on the growth of vegetation (trees tend to block the signal). We also
recommend configuring the data logger in such a way that the 2G/3G/4G field strength is recorded during
data transfer. In this way you can get an early warning when the field strength gets low.
What to do to get a better field strength signal;
•
Make sure the antenna is mounted in accordance with the manufacturer’s instructions. Note there are
antennas (whip antennas) that require a metal surface below the antenna; others (dipole antennas) do
not.
•
Make sure that all connectors on the antenna and antenna cable are tightened and free of moisture.
•
Make sure the antenna is in vertical position; as the GSM and 2G/3G/4G radio signals are vertically
polarize, the antenna should be vertical positioned for maximum performance.
•
Do not place the antenna near metal surfaces or structures. Be aware that various building structures
contain metal (e.g. steel mesh as reinforcement for concrete).
•
Place the antenna outdoors.
•
Identify the nearest GSM tower of your provider. Place the antenna in a location that provides a free
line-of-sight to the tower.
•
If you cannot identify the nearest GSM tower of your provider, place the antenna on a higher position;
generally, higher is better.
•
Use good quality (low-loss) antenna cables. Generally, the thicker the cable, the better.
•
Avoid unnecessary adaptors and connectors in the antenna cable, as every “joint” cause a significant
signal loss (0.5 to 1 dB).
•
Use an antenna with a higher antenna gain. (simple stubby antennas can have a gain of -9db, a rod
antenna can have an antenna gain of 0 or 4 dB or higher; Note that the allowed radio power is limited
to 1W/2W. An antenna with a higher gain is only allowed when this only compensates for the cable and
connector losses).
•
Seal your antenna-connector with vulcanizing tape, to prevent from oxidation.
•
When the integrated antenna is used, make sure that the data logger is NOT mounted on a metal plate.
•
When the data logger is encapsulated in a metal enclosure or cage of faraday, you may NOT use the
integrated antenna, but you must use an external antenna to avoid damaging the MODEM
.
Make sure the SIM you intend to use is compatible with your network and the pin code protection is
disabled.
