AT Commands Reference Manual - wireless netcontrol GmbH

Hardware Information
+IPR:
(1-8,10-14,16-18,300,600,1200,2400,4800,9600,19200,38400,57600,115200,230400,460800,921600,3200000,
3686400)
OK
&K, RTS/CTS Flow Control
This command configures the flow control. The RTS (Request To Send) is an input line. The RTS
signal is received from the terminal and a low condition indicates that the H24 can send more
data. The CTS (Clear To Send) is an output line. The CTS signal is sent to the terminal and a low
state indicates that more data can be sent to the H24.
The RTS and CTS together make up what is called RTS/CTS or “hardware” flow control. Both
lines are used when “hardware flow control” is enabled in both the terminal and the H24 devices.
When the terminal is ready and able to receive data, it puts the RTS line in an active (low)
condition to indicate this to the H24. If the terminal is not able to receive data (typically because
its receive buffer is almost full), it puts the RTS line in an inactive (high) condition as a signal to
the H24 to stop sending data. When the terminal is ready to receive more data (for example, after
data has been removed from its receive buffer), it places this line back in the active condition. The
RTS line complements the CTS line. The H24 puts the CTS line in an active condition to tell the
terminal that it is ready to receive the data. Likewise, if the H24 is unable to receive data, it places
the CTS line in an inactive condition.
Note: This command can only be issued over UART.
Command Type Syntax Response/Action
Set AT&K OK
Read AT&K? &K:
Test AT&K=? &K: (list of supported
s)
The following table shows the &K parameters.
Table 3-97: &K Parameters
Description
0 Disable all terminal/H24 flow control
3 Enable CTS/RTS terminal/H24 flow control
6 Enable CTS/RTS terminal/H24 flow control
The default value is 3.
Example
AT&K?
&K: 3
OK
AT&K4
OK
3-160 H24 - AT Commands Reference Manual April 15, 2010