Watchdog II Mesh User Manual
P/N 86-0006-00
Rev E 01-2020
Page
7 of 38
Elecsys’ units will work on GSM networks throughout most Europe, South America, Asia, and the
Middle East, though it depends on the roaming agreements that the local GSM carriers have with AT&T
and O2/Telefonica. Contact Elecsys for specific guidance regarding GSM operations in areas outside
of North America.
1.3.2
Inmarsat Satellite using ISatM2M data protocol
For extremely remote areas, or
anywhere in the world,
Elecsys offers a cost-effective satellite option:
Inmarsat IDP service. Inmarsat is the major satellite operator for international maritime and aviation
communications, and its satellite network offers global coverage using geostationary satellites, spaced
around the world over the equator. Inmarsat IDP is a two-way, short data packet service that is ideally
suited for remote monitoring applications.
The satellite equipped Base Station uses a small (6 in. [15 cm] diameter), low power Skywave satellite
modem to transmit data to and receive commands and configurations from the WatchdogCP website.
It must be pointed to the nearest satellite just like a satellite TV dish.
1.3.3
Modbus based SCADA system using a Modbus data radio
The Watchdog II RMU can also be configured to work as a Modbus slave RTU. The RMU is interfaced
to a user-supplied data radio using its RS-232 radio modem interface. Once properly configured, the
user is able to read and write to Modbus register and coil locations to acquire up to 16 channel values,
change the alarm settings, etc.
