Hi,
Does anyone know what is actually behind the 'SIM Failure' error (CME code 013) from the SM5100B GSM module?
I get it occasionally when I try to send an SMS message. I know the obvious answer is "there's something wrong with the SIM card" but there must be more to it than that. I can happily talk to the SM5100B module, I can read the IMSI and IMEI, I can receive and read SMS messages and I know I have plenty of credit and I know I'm registered to the network.
All of this suggests everything is working fine, but when I send a message I get frequent failures (about 1 failure for every 5 attempts), the message is always just a simple 'SIM failure' nothing useful ! I've tried different SIM cards, and I've tried different GSM modules, but there seems to be no observable pattern in the failures.
The fact that I can receive and read SMSs suggest there's no physical problem with the card, (unless there some unique functionality of the card that only comes into play during a send)
Currently my best guess is that this is general purpose error message used for any error that doesn't fit into any of the other 100 or so pre-defined catogories. I've run out of (or ruled out) things I can think of that might be wrong at my end, and bearing in mind that I normally get the error about 12-15 seconds after trying to send the message I'm wondering if it's actually generated as a response to something happening on the GSM network.
Does anyone have an other suggestions? or, even better, does anyone know what the cause is?
Thanks
Thanks for the suggestions.
I don't think it's dodgy hardware - I get the same issues with different SIMs, and with different shields. Also, since I can successfully receive, read and process SMS messages, my guess is that the coms between the SIM card and the GSM module are OK.
I hadn't though about the power issue before, but I do get a high signal strength, which means (I think) that my transmit power doesn't have to be very high to transmit.
I've been thinking that maybe I get the message if the phone I'm sending to is out of range or off the network or switched off?
Does anyone know how GSM networks work? If I attempt to send a message to someone who's phone is switched off, I assume the network will cache the message, and then deliver it as soon as it detects the receiving phone is back on the network? Or does it reject the message when it gets sent and cause the transmitting module to return an error?
I've been thinking that maybe I get the message if the phone I'm sending to is out of range or off the network or switched off?
Well try it send messages to your own phone with it on/off. See what happens. But getting some kind of "general" error messages because the other phone is off is not my feeling of how these things work.
I hadn't though about the power issue before, but I do get a high signal strength, which means (I think) that my transmit power doesn't have to be very high to transmit.
The rx signal strength does not mean you need less power when transmitting!.
Mark
From uk.ask.com http://uk.ask.com/question/what-does-sim-error-mean
A SIM error is an error message displayed on cellular phones if the SIM card is inserted inappropriately, if the SIM card is dirty, if the battery of the phone is defective or if the PIN has been entered incorrectly 3 times.
Which takes you back to my first answer. And I do think its you not the network!
The only other thing that I can think of is electrical "noise", so maybe more decoupling?
Mark
The rx signal strength does not mean you need less power when transmitting!
Doesn't it? I understood that GSM devices would work out how close they were to a base-station by looking at the signal strength, and then adjust their output power appropriately to conserve power - that's why if you take your phone to a remote location the batteries go down more quickly.
And I do think its you not the network!
Could be, I can solder as badly as the next guy! But if it really is a hardware issue, why do I get it with different SIMs and different shields? and why is it only when I attempt to send an SMS? All the other actions/commands that involve the SIM card work perfectly.
I've done some experimentation. If I send a message to my switched-off phone, then I still get the message at about the normal frequency, however if I send it to my moms mobile phone (that has been switched off and left in a draw since I gave it to her) then I get the message almost every time I attempt a send. I also get the message if I send to a random made-up phone number.
I've done some experimentation. If I send a message to my switched-off phone, then I still get the message at about the normal frequency, however if I send it to my moms mobile phone (that has been switched off and left in a draw since I gave it to her) then I get the message almost every time I attempt a send. I also get the message if I send to a random made-up phone number.
So how many times do you get the erorr message whaen you send from your own phone to your moms? Not from the rig your having trouble with but your day to day phone?
Doesn't it? I understood that GSM devices would work out how close they were to a base-station by looking at the signal strength, and then adjust their output power appropriately to conserve power - that's why if you take your phone to a remote location the batteries go down more quickly.
That may be true for over all power consumption, but it tells us nothing about the PEAK power requirement which I would expect to see when you start to send.
Mark
Nice name.
It was that or Incontinentia Buttocks.
So how many times do you get the erorr message when you send from your own phone to your moms? Not from the rig your having trouble with but your day to day phone?
My day-to-day phone is a smartphone. If I use that to send a message to a long-time disconnected phone (or a made-up number) then I don't get an error message just a red blob next to the message and an exclamation mark. The true error message (the low-level CME code) remains hidden.
Regards