NPort IA5150/5250 Series User’s Manual
Web Console Configuration
5-27
Ethernet Modem Mode
Dial-in
NPort IA5150/5250 listens for a TCP/IP connection request from the remote Ethernet modem or
host. NPort IA5150/5250’s response depends on the ATS0 value, as outlined below.
ATS0=0 (default):
NPort IA5150/5250 will temporarily accept the TCP connection and then send the “RING” signal out
through the serial port. The serial controller must reply with “ATA” within 2.5 seconds to accept the
connection request, after which NPort IA5150/5250 enters data mode. If no “ATA” command is received,
NPort IA5150/5250 will disconnect after sending three “RING” signals.
ATS0
≧
1:
NPort IA5150/5250 will accept the TCP connection immediately and then send the “CONNECT
<baud>” command to the serial port, in which <baud> represents the baud rate of NPort
IA5150/5250’s serial port. After that, NPort IA5150/5250 immediately enters data mode.
Dial-out
NPort IA5150/5250 accepts the AT command “ATD <IP>:<TCP port>” from the serial port and
then requests a TCP connection from the remote Ethernet Modem or PC. This is where <IP> is the
IP address of the remote Ethernet modem or PC, and <TCP port> is the TCP port number of the
remote Ethernet modem or PC. Once the remote unit accepts this TCP connection, NPort
IA5150/5250 will send out the “CONNECT <baud>” signal via the serial port and then enter data
mode.
Disconnection request from local site
When NPort IA5150/5250s is in data mode, the user can drive the DTR signal to OFF, or send
“+++” from the local serial port to NPort IA5150/5250. NPort IA5150/5250 will enter command
mode and return “NO CARRIER” via the serial port, and then input “ATH” to shut down the TCP
connection after 1 second.
NOTE
The “+++” command cannot be divided. The “+” character can be changed in register S2, and the
guard time, which prefixes and suffixes the “+++” in order to protect the raw data, can be changed
in register S12.
Disconnection request from remote site
After the TCP connection has been shut down by the remote Ethernet modem or PC, NPort
IA5150/5250 will send the “NO CARRIER” signal via the serial port and then return to command
mode.
The following tables give the additional parameters that can be configured for TCP Client Mode.
Refer to the table below the figures to see details of the meaning of each parameter.