Sena HelloDevice Pro PS110 Series User Manual page 64

  Flow control
The f actory default setting of the flow control is None. Software Flow Control using XON/XOFF
and hardware flow control using RTS/CTS are supported by the Pro Series.
Software flow control method controls data communication flow by sending special characters
XON/XOFF (0x11/0x13) between two connected devices. And hardware flow control method
controls data communication flow by sending signals back and forth between two connected
devices.
Note:
Flow control is supported only in RS232 and RS422 mode. RS485 mode does not support any
kind of flow control method.
  DTR/DSR behavior
Purpose of the DTR/DSR pin is to emulate modem signal control or to control TCP connection
state by using serial port signal. The DTR is a write-only output signal, whereas the DSR is a
read-only input signal in the Pro Series.
The DTR option can be set to one of three types: always high, always low or high when TCP/UDP
is opened. If the DTR behavior is set to high when TCP/UDP is opened, the state of the DTR pin
will be maintained high if the TCP/UDP connection is established.
The DSR input behavior can be set to one of two types: none or allow TCP/UDP connection only
by high. If user sets the DSR input behavior as Allow TCP/UDP connection only by HIGH, TCP
connection to remote host from Pro Series is made only when the DSR status is changed from
low to high. And TCP connection to remote host is disconnected when the DSR status is changed
from high to low. And also Pro Series accepts TCP connection from the remote host only when
the DSR status is high. In case of UDP mode, Pro Series receives UDP data from the remote host
only when the DSR status is high. But In modem emulation mode, the connection to the remote
host will be disconnected when the DSR status is changed from high to low regardless of the
value of DSR behavior.
Serial device connected to Pro Series can control TCP/UDP connection of Pro Series by
controlling DTR signal of it.
Note:
1. DTR/DSR behavior configuration will not be effective when the modem is enabled.
2. DTR/DSR behavior does not effective in RS422 and RS485 mode.
  Inter-character timeout
This parameter defines the interval the Pro Series fetches the overall serial data from its internal
buffer. If there is an incoming data through the serial port, the Pro Series stores data into the
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