NPort 5000 Series User Manual
Disconnection Request from the Local Site
When the NPort is in data mode, the user can drive the DTR signal to OFF, or send +++ from the local
serial port to the NPort. The NPort 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 the Remote Site
After the TCP connection has been shut down by the remote Ethernet modem or PC, the NPort will send the
NO CARRIER signal via the serial port and then return to command mode.
AT Commands
The NPort supports the following common AT commands used with a typical modem:
Dial up the IP address: Port No.
3 ATE
ATE1=Echo ON (default)
4 ATH
ATH1=Off-hook
Set Pulse/Tone Dialing mode
Quiet command (default=ATQ0)
Change the contents of S register
Read the contents of S register
13 ATV
ATV0 for digit code
ATV1 for text code
0=OK
1=connect (default)
2=ring
3=No carrier
4=error
14 ATZ
Reset (disconnect, enter command mode and restore
the flash settings)
15 AT&C
Serial port DCD control AT&C0=DCD always on
AT&C1=DTE detects connection by DCD on/off
(default)
16 AT&D
Serial port DTR control AT&D0=recognize DTE always
ready AT&D1, AT&D2=reply DTE when DTR On
(default)
Restore manufacturer’s settings
Serial port RTS option command
Write current settings to flash for next boot up