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FIBOCOM L610-LA Series Hardware Guide
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information, the module will register on the network. When the USIM_PRESENCE is in low level, the
module judges that the SIM is removed, then it will not read the SIM.
Note:
The USIM_PRESENCE is in active high by default, and can be switched to active low by AT
command.
AT Command
Function Description
AT+GTSET=”SIMPHASE”,1 Default, high level detection
AT+GTSET=”SIMPHASE”,0 Low level detection
3.5.4 USIM Design Requirements
SIM circuit design shall meet EMC standards and ESD requirements, and at the same time, shall improve
anti-interference ability to ensure that the SIM can work stably. The design needs to strictly observe the
following rules:
SIM card slot is placed as close to the module as possible, away from the RF antenna, DCDC power,
clock signal cables and other strong interference sources;
Adopt the SIM card slot with metal shield shell to improve anti-interference ability;
The length of cable from the module to the SIM card slot shall not exceed 100mm. Longer cable will
reduce signal quality;
USIM_CLK and USIM_DATA signals are ground isolated to avoid mutual interference. If it is difficult
to do so, SIM signal needs to be ground protected as a set;
The filter capacitor and ESD device of SIM signal cable are placed close to the SIM card slot. Select
22~33pF capacitor for ESD device equivalent capacitor.
3.6 UART Interface
3.6.1 UART Interface Definition
L610 module has three serial ports: Main serial port, UART3 and Debug serial ports. The following
describes the main features of these two serial ports:
The Main serial port and UART3 support 0,2400,4800,9600,14400,19200,28800,
33600,38400,57600,115200, 230400,460800,921600,1000000 baud rates.
The default baud rate is 115200bps, used for data transmission and AT command transmission.
The Debug serial port supports 115200bps baud rate for FIBOCOM internal debugging.