Vaisala Hydromet Data Collection Platform - Manual (Page 118)

User's Guide ______________________________________________________________________
116 __________________________________________________________________M210784EN-E
6. Communication is not working properly.
a. Whenever possible, use an external device to verify that the
communication infrastructure is working properly. For
example, use a cellular phone to verify that the signal strength
in the site is sufficient or that the system SIM card has access
to the network.
b. Troubleshoot the modems as instructed below.
To test the GSM modems with the AT commands, refer to
Table 24 on page 116 . The faulty GSM modems are not
serviceable in the field; if they do not operate correctly, you
must return them to Vaisala for repairs.
To monitor different command sequences, check the Extra
op. Info to COM0 option in modem configuration. This
enables the modem control software to output status
information to the fixed RS-232 port, that is, COM0. For
example, you can monitor what is sent to the modem and how
it responds. The printout includes additional internal debug
data. Note that the output is sent only when the service
connection is closed.
c. If the communication device supports ASCII commands, for
example, AT commands for modems, this command interface
Table 24 Test Commands for GSM Modems
Parameter Command Value
Network registration AT+CREG=? Registration status: <n>, <stat>,
where <stat>
0 = Not registered
1 = Registered to home network
2 = Searching
3 = Registration denied
5 = Registered, roaming
Available operator AT+COPS? Returns the used operator
AT+COPS=? Queries all available operators, can
be used to refresh the connection
Operator selection AT+COPS=0/1 0 = Automatic
1 = Manual
Signal quality AT+CSQ Receive level
31 = Best
0 = Worst
99 = Not known
Under normal conditions, value
should be 10 or above.