Specifications

Smart Machine Smart Decision
SIM900_AT Commands Manual_V1.07 17 2012.12.10
Ensure that any communications software package (e.g. Hyper terminal) uses software flow
control.
NOTE:
Software Flow control should not be used for data calls where binary data will be transmitted or
received (e.g. TCP/IP) as the DTE interface may interpret binary data as flow control characters.
1.6.2 Hardware flow control (RTS/CTS flow control)
Hardware flow control achieves the data flow control by controlling the RTS/CTS line. When the
data transfer should be suspended, the CTS line is set inactive until the transfer from the receiving
buffer has completed. When the receiving buffer is ok to receive more data, CTS goes active once
again.
To achieve hardware flow control, ensure that the RTS/CTS lines are present on your application
platform.