LTE-A Module Series
EM121R-GL Hardware Design
EM121R-GL Hardware Design 36 / 80
Parameter
1. Hot-plug function is invalid if the configured value of
<insert_level>
is inconsistent with hardware
design.
2. Hot-plug function setting takes effect after the module is restarted.
3. The underlined value is the default parameter value.
4. USIM_DET[1:2] is pulled LOW by default, and will be internally pulled up to 1.8 V by software
configuration only when (U)SIM hot-plug is enabled by
AT+QSIMDET
.
4.1.3. Normally Closed (U)SIM Card Connector
With a normally closed (U)SIM card connector, the USIM_DET is normally short-circuited to ground when
a (U)SIM card is not inserted, (U)SIM card detection by high level is applicable to this type of connector.
After executing
AT+QSIMDET=1,1
to enable the (U)SIM hot-plug: when a (U)SIM card is inserted,
USIM_DET will change from low to high level; when the (U)SIM card is removed, USIM_DET will change
from high to low level.
⚫
When the (U)SIM is absent, CD is short-circuited to ground and USIM_DET is at low voltage level.
⚫
When the (U)SIM is inserted, CD is open from ground and USIM_DET is at high voltage level.
The following figure shows a reference design of (U)SIM interface with a normally closed (U)SIM card
connector.
Maximum Response Time
300 ms
Characteristics
The command takes effect after the module is restarted.
The configuration will be saved to NVRAM automatically.
<enable>
Integer type. Enable or disable (U)SIM card detection.
0 Disable
1 Enable
<insert_level>
Integer type. The level of (U)SIM detection pin when a (U)SIM card is inserted.
0 Low level
1 High level
NOTES