User Manual

2. SYSTEM CONNECTOR INTERFACE
55
LZT 123 7263 R1A
RTS and CTS are capable of transmitting at 1/10th of the data
transmission speed for data rates up to 460kbit/s (byte-oriented flow
control mechanism).
Switching times for RTS and CTS
The table below shows the switching times.
Request to Send (RTS)
Used to condition the DCE for data transmission. The default level is
high by internal pull up.
The exact behaviour of RTS is defined by an AT command. Software
of hardware control can be selected. Hardware flow is the default
control.
The application must pull RTS low to communicate with the module.
The module will respond by asserting CTS low, indicating it is ready for
communication.
Clear To Send (CTS)
CTS indicates that the DCE is ready to transmit data. The default level
is high. You can define the exact behaviour of CTS through an AT
command, and can select software or hardware flow control.
The table below shows the load characteristics for this signal.
Parameter Limit
Time from Low to High level <2µs
Time from High to Low level <2µs
Parameter Limit
Application driving impedance <100Ω
Input capacitance <2nF
Input resistance (pull-up) 100kΩ to VCC
Parameter Limit
Application load capacitance <500pF
Application load resistance ≥1MΩ