Data Mode (Usdg Mode) - Advantech ADAM-4571 User Manual

Round-Robin mode:
Enabling "Response Timeout" parameter, the ADAM-4570 series will
operate in "Round-Robin mode". Each serial port supports up to five
simultaneous connections, so multiple hosts can transmit/receive data to/
from the same serial port simultaneously. Every host can transmit data to
the same serial port simultaneously, but the ADAM-4570 series will pro-
cess the data communication in order. ADAM-4570 series will process
the first host's request and reply the response to the first host. ADAM-
4570 serial device server can determine the end of the serial acknowl-
edgement via response timeout. When ADAM-4570 serial device server
receives nothing from serial port after the setting of response timeout, the
device will reply the acknowledgement to the host and then process the
next host's request. While the connected hosts are more and "Response
Timeout" is long, the process time is much longer.
Frame Break is a very import parameter for Round Robin mode. This
parameter is the smart way to reduce inefficient waiting time and the
ADAM-4570 series can transmit data more efficiently. Disabling the
Frame Break function, the ADAM-4570 series will wait "Response Tim-
eout" period, whether the device have transmitted the data. During this
period, the commands from hosts will be queued and the ADAM-4570
series just processes this command. Enabling "Frame Break", if the serial
port idle is longer than the "Frame Break" period, ADAM-4570 series
will assume the communication is completed and continue the next host's
query. This is an efficient way to reduce the waiting time and improve the
performance.

3.4.3 Data Mode (USDG Mode)

(Only ADAM-4571 and ADAM-4570 support this function)
The ADAM-4571/4570 can be Data Server or Data Client either. Both
operations support TCP and UDP protocol. The ADAM-4571/4570
makes your serial devices behave just like networking devices. You can
issue commands or transmit data from serial devices, which connected to
the ADAM-4571/4570, to any devices that are connected to the Internet.
The ADAM-4571/4570 allows most 5 host PCs accessing data simulta-
neously via polling networking architecture. You can use it according to
your application. If you want to access the ADAM-4571/4570, you must
ascertain your application software supports standard networking appli-
cation programming interface (API) such as: WinSock Socket.
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