Specifications

ISU AT Command Reference Phase III AT Commands
Iridium Proprietary Version 2.45
20 June 2011 54
7.8 +CSQ - Signal Quality (Initial implementation; revised in Phase VI)
Exec Command: +CSQ
Execution command returns the received signal strength indication <rssi> from the ISU. Response is in the
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.
Test Command: +CSQ=?
List the supported signal strength indications. The response is in the form:
+CSQ: (supported <rssi>s)
Note: A signal strength response may not be immediately available, but will usually be received 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.