New iridium modem problem

SPARK-X
1

We have two of these modems bought in 2019 and they work exactly as stated in the user interface documentation. Recently we bought two more modems and they don’t work. I found two cases where a command triggered an echo of that command rather than a result. When I found a third violation, I gave up.

Details:

  • We clear the MT message buffer by sending the modem AT+SBDD1. The response should be 0 for success or 1 for failure. Instead we receive AT+SBDD1. So, the modem echoes our command rather than sending us the expected result. See page 82 of the reference.

  • We enable spontaneous event reporting, signal quality, and network status by sending the modem AT+CIER=1,1,1. It should respond with +CIEV:1,0 (network service currently unavailable) or +CIEV:1,1 (network service is available. See page 36 of the reference. Instead, we get a response of +CIER=0,0,0, our command to the modem to disable spontaneous event reporting, signal quality, and network status.

I did contact the manufacturer a week ago but no response.

Rick Sparber

2

Hi Rick,

I’m not really sure how we can best help, but we will if we can.

Which product do you have? Do they have 9602 or 9603N modems on them?

Are you using your own code, or are you using our Arduino IridiumSBD library and code examples? (I assume you’ve written your own code?)

What do you see if you send “AT+CGMR” - both on your old working modems and these new problematic ones?

What does “AT+CIER?” get you - after your “AT+CIER=1,1,1” ?

How about “AT+CIER=?” ?

Best wishes,

Paul

3

Paul,

I beleive all of the modems are 9602. I don’t see any markings on the devices to confirm this but the boards match what I found in a picture on the web.

Yes, I’m using my own code, about 15 KB for the modem.

For one of the new modems I get:

Modem Revision AT+CGMR

Call Processor Version: TA21004

Modem DSP Version:

List the supported settings AT+CIER=?

+CIER:(0-1),(0-1),(0-1),(0-1),(0-1)

OK

current indicator event reporting settings are AT+CIER?

+CIER:0,0,0,0,0

OK

I do turn on reporting, get a reading, and then turn it off.

I can’t run these test on the old modems until Monday, assuming they survive the weekend’s launch.

I’m still bothered by what appears to be two versions of the modem. One version meets the stated interface docs and the other does not.

Thanks for your help,

Rick

4

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

5

Paul,

I added the command to turn off echo and now the modems work as expected!

Thanks for your help,

Rick

6

No problem Rick - glad that’s working for you.

Good luck with your launch!

Paul