Vaisala Hydromet Data Collection Platform User Manual
Page 32
User's Guide ______________________________________________________________________
30 __________________________________________________________________ M210933EN-C
The PSTN modem is a dial-up modem for the weather stations and other
systems. The operation mode and settings can be selected with the
extended set of AT commands. The PSTN modem is used to connect the
weather station to public switched telephone networks (PSTN) or to a
leased line point-to-point application.
The PSTN modem unit has a small metal enclosure. The modem is
mounted on a DIN rail inside the equipment enclosure. It has been
designed for demanding environments. It is rated for -40 to +60 °C
operating temperatures. The modem is DC-powered and has low power
consumption.
The PSTN modem module has face connectors where the power supply
and RS-232 can be connected. There is also a RJ-11 connector for the
telephone interface.
The module includes both data compression and data correction
functions. The maximum data rate is up to 57.6 Kbits/second. The line
input is protected by a telecom PTC fuse, sidactors, and a heavy-duty
350 V discharge tube.
When connecting the PSTN modem to the QML logger, you need to use
the terminal strip to provide power for the modem. There is an initial
surge arrester to protect the line connection. For the example wiring
diagram, see
Chapter 7, Technical Data, on page 337
.
After the cables are connected, configure the PSTN modem with Lizard
Setup Software. Refer to