Ri And Dtr Behavior - Sunsea AIoT SIMCom SIM7600NA User Manual

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Figure 16: level matching circuit
To comply with RS-232-C protocol, the RS-232-C level shifter chip should be used to connect
MODULE to the RS-232-C interface, for example SP3238ECA, etc.
Note1: User needs to use high speed transistors such as MMBT3904.
Note2: MODULE supports the following baud rates: 300, 600, 1200, 2400, 4800, 9600, 19200,
38400, 57600, 115200, 230400, 460800, 921600, 3200000, 3686400, 4000000bps. The default
band rate is 115200bps.
3.3.2

RI and DTR Behavior

The RI pin can be used to interrupt output signal to inform the host controller such as application
CPU.
Normally RI will keep high level until certain conditions such as receiving SMS, or a URC report
coming, and then it will change to low level.
Figure 17: RI behaviour（SMS and URC report）
SIM7600NA_user manual _V1.00 31 2020-1-7