Multi-Tech Systems GPRS (MTSMC-G) ユーザーズマニュアル

Chapter 3 – General Behaviors 

Multi-Tech Systems, Inc. Wireless GSM/GPRS AT Commands (Document Number S000293I) 

11 

 

SIM card Insertion and Removal procedures are supported. Software functions rely on positive reading of the hardware 
SIM detect pin. This pin state (open/closed) is permanently monitored. 

When the SIM detect pin indicates that a card is present in the SIM connector, the product tries to set up a logical SIM 
session. The logical SIM session will be set up or not depending on whether the detected card is a SIM Card or not. The 
AT+CPIN? command delivers the following responses: 

• 

If the SIM detect pin indicates “absent”, the response to AT+CPIN? is “+CME ERROR 10” (SIM not inserted). 

• 

If the SIM detect pin indicates “present”, and the inserted Card is a SIM Card, the response to AT+CPIN? is 
“+CPIN: xxx” depending on SIM PIN state. 

• 

If the SIM detect pin indicates “present”, and the inserted Card is not a SIM Card, the response to AT+CPIN? is 
CME ERROR 10. 

• 

These last two states are not given immediately due to background initialization. Between the hardware SIM 
detect pin indicating “present” and the previous results the AT+CPIN? sends “+CME ERROR: 515” (Please wait, 
init in progress). 

When the SIM-detect pin indicates card absence, and if a SIM Card was previously inserted, an IMSI detach procedure is 
performed, all user data is removed from the product (Phonebooks, SMS etc.). The product then switches to

mode. 

When the hardware SIM detect pin is not managed, the software cannot know the state of the SIM (SIM inserted or SIM 
removed) except for the initialization of the modem. In this case, the SIM must be present in the rack before the 
initialization of the modem can be taken into account.  

If the SIM is removed and it had been detected at the time of initialization of the modem, the following message is 
displayed: +CME ERROR: 13. If the SIM is inserted in the rack and it was not present at the time of the initialization of the 
modem, the state of the SIM remains unchanged (SIM removed). It will have to initialize the modem again so that it is 
detected.  

After entering the PIN (Personal Identification Number), some SIM user data files are loaded into the product 
(Phonebooks, SMS status, etc.). Please be aware that it might take some time to read a large phonebook. 

The AT+CPIN? command response comes just after the PIN is checked. After this response user data is loaded (in 
background). This means that some data may not be available just after PIN entry is confirmed by ’OK’. The reading of 
phonebooks will then be refused by “+CME ERROR: 515” or “+CMS ERROR: 515” meaning, “Please wait, service is not 
available, init in progress”. 

This type of answer may be sent by the product at several points:  

• 

When trying to execute another AT command before the previous one is completed (before response), 

• 

When switching from ADN to FDN (or FDN to ADN) and trying to read the relevant phonebook immediately,  

• 

When asking for +CPIN? status immediately after SIM insertion and before the product has determined if the 
inserted card is a valid SIM Card. 

Phone numbers can consist of up to 60 digits. The first 20 digits are stored in the SIM in the phonebook file (EF

ADN

, EF

FDN

 

or EF

LND

) corresponding to the selected phonebook. The next digits are stored in other extension SIM files (EF

EXT1

 or 

EF

EXT2

). 

  

1 to 20 

1 

0 

21 to 40 

1 

1 

41 to 60 

1 

2 

If there are no more free records in the EF

EXT1

, the behavior is: 

• 

if the user tries to store an entry that exceeds 20 digits:  +CME: 20 

• 

if the user tries to dial an number that exceeds 20 digits:  +CME: 20