Specifications

ISU AT Command Reference Phase VI AT Commands
Iridium Proprietary Version 2.45
20 June 2011 77
form:
+CSQ: <rssi>
where <rssi> is:
0 Equivalent to 0 bars displayed on the ISU signal strength indicator.
1 Equivalent to 1 bar displayed on the ISU signal strength indicator.
2 Equivalent to 2 bars displayed on the ISU signal strength indicator.
3 Equivalent to 3 bars displayed on the ISU signal strength indicator.
4 Equivalent to 4 bars displayed on the ISU signal strength indicator.
5 Equivalent to 5 bars displayed on the ISU signal strength indicator.
Note: The +CSQ form of the command waits for an updated signal strength reading to become available.
This will usually be within two seconds of issuing the command. If the ISU is in the process of acquiring
the system, or in a satellite handoff, a delay in response of up to 10 seconds may be experienced.
If the ISU has no SIM, is awaiting a SIM PIN entry, has an invalid SIM, or has otherwise not proceeded to
successful registration, the delay in response may exceed the 50 second timeout limit. Under such
condition, an ERROR response will be received. To avoid a delayed response due to registration problems,
issue the +CREG command to verify registration prior to entering the +CSQ command to obtain signal
strength.
Note: The +CSQF form of the command returns immediately, reporting the last known signal strength.
Test Command: +CSQ=?
List the supported signal strength indications. The response is in the form:
+CSQ: (supported <rssi>s)
10.5 +CULK – Unlock
Exec Command: +CULK=<unlock key>
Unlock the SBD functionality of the ISU after it has been locked by the Gateway. The unlock key must be
obtained by contacting Iridium’s customer support.
<unlock key>:
0000000000000000 .. FFFFFFFFFFFFFFFF
A string of 16 hexadecimal digits.
While the ISU is locked, it is unable to perform any SBD sessions. Any attempts to start a session will
return an error code indicating that the ISU is locked.
Command Response:
+CULK:<status>
where:
<status> indicates the lock status of the ISU following the unlock attempt:
0 Unlocked – ISU is not locked and is permitted to perform SBD sessions.
1 Locked – ISU is locked and unable to perform SBD sessions. It must be unlocked by
supplying the correct unlock key to the +CULK command.
2 Permanently locked – ISU is locked and unable to perform SBD sessions. It cannot be
unlocked and must be returned to the supplier.
Read Command: +CULK?