Hi Rick,
OK - thanks. Can you please confirm that the boards you bought from us are https://www.sparkfun.com/products/13745 ? Assuming they are, then, yes, that is the Iridium 9602 modem. We have other products, including our own, which use the smaller 9603N modem.
It does sound as if your modems are running newer firmware, and are possibly providing different responses.
I can only find copies of the AT Command Reference dated 2014. Nothing newer than that. Nothing to indicate that the responses might have changed…
Here is what I see with a 9603N modem dating from around 2017. I typed the AT+ commands into a terminal emulator, they are echoed back by the modem as I type.
AT+CGMI
Iridium
OK
AT+CGMM
IRIDIUM 9600 Family SBD Transceiver
OK
AT+CGMR
Call Processor Version: TA16005
Modem DSP Version: 1.7 svn: 2358
DBB Version: 0x0001 (ASIC)
RFA Version: 0x0007 (SRFA2)
NVM Version: KVS
Hardware Version: BOOT07d2/9603NrevDE/04/RAW0c
BOOT Version: TA16005 (rev exported)
OK
AT+SBDD1
0
OK
AT+CIER=1,1,1
OK
+CIEV:0,0
+CIEV:1,0
Your firmware (TA21004) is much newer than mine (TA16005).
Could this be just an “Echo” issue? By default, Echo is enabled. The modem echos back the AT command, then sends the response. You can disable the Echo by sending “ATE0”, and re-enable them with “ATE1”. Is your code sending ATE0 ? Maybe you are sending it too early, or not sending it? And/or are you waiting for the full response, and expecting the echo at the beginning? Maybe your old modems have echo disabled, and these newer ones have it enabled?
How would you like to proceed? We can contact Ground Control - formerly Rock7 - and ask them if they have an updated copy of the AT Command Reference. But I doubt if anything has changed…
Apologies for the inconvenience - and I hope this helps,
Paul