Opened and Closed States of the Serial Port

Depending on the current setup and data connection state the serial port of the DS may be opened or closed. When the serial port is opened it is ready to record incoming data into the serial-to-Ethernet buffer* when in the data routing mode or accept a serial command when in the serial programming mode. When the serial port is closed it ignores all incoming serial data except the escape sequences (when enabled through the Soft Entry (SE) setting ).

The following details when the serial port is closed or opened:

When the serial port is in the serial programming mode it is always opened (i.e. ready to accept programming commands);
When the serial port is in the data routing mode:
While the IP-address is being obtained from the DHCP server** the port is closed;
After the IP-address has been obtained successfully:
If the current Routing Mode (RM) [setting/ parameter] is 0 (server):
If the data connection is not established the port is closed;
If data connection is established the port is opened;
If the current Routing Mode (RM) is 1 (server/client) or 2 (client):
If the Connection Mode (CM) setting is 0 (immediately) or 1 (on data or command) the port is opened;
If the Connection Mode (CM) setting is 2 (on command) or 3 (on command or DSR=HIGH):
If the data connection is not established the port is closed;
If the data connection is established the port is opened.

* Not all incoming data will necessarily be recorded into the buffer- see serial-to-Ethernet data routing

** Happens at startup when the DHCP (DH) setting is 1 (enabled)