INSYS GSM 4.3
Functions
12.6
Data Flow Control (Handshake)
The data flow control ensures that the data transfer is interrupted as soon as the
modem buffer exceeds a certain level. Two data flow control options are available:
Via the control lines RTS and CTS, or via the control characters XON/XOFF which
are inserted into the data stream.
12.6.1
Hardware Data Flow Control (RTS/CTS)
The hardware data flow control works in two directions. When the critical buffer
level is exceeded, the modem will set the CTS line to "low" and will thus indicate to
the application to interrupt the data flow. When the buffer is emptied sufficiently
for the INSYS GSM 4.3 to be able to receive data again, the CTS line is set to
"high". Reversely, the application can also indicate to the INSYS GSM 4.3 to inter-
rupt the data flow. This is done via the RTS line. If it is set to "low", the modem will
interrupt the data flow to the application. The application will set it to "high" to re-
quest data from the INSYS GSM 4.3.
The data flow control with RTS/CTS behaviour is active by default.
Configuration with HSComm
Select the type of data flow control or switch it off completely on the
"Basic Settings" tab in the "Handshake" panel.
Configuration with AT commands
To switch the data flow control on and to
set the type to RTS/CTS, use
AT\Q3
To switch the data flow control off, use
AT\Q0
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