NavCom Sapphire Rev.J - Manual (Page 103)

Sapphire Technical Reference Manual Rev. J
103
Defaults:
If NVRAM is clear, the defaults are the following:
[ETHVCOM] ON, 0.0.0.0, 0, UDP2, 4361, ETH1
[ETHVCOM] OFF, 0.0.0.0, 0, UDP2, 4362, ETH2
[ETHVCOM] OFF, 0.0.0.0, 0, TCP1, 4363, ETH3
[ETHVCOM] OFF, 0.0.0.0, 0, TCP1, 4364, ETH4
If the command is typed without specifying the port, it defaults to ETH1. Any other
parameter not specified is not changed.

Entering this command without any arguments displays the current settings for all
four logical ports.
Table 63: ETHVCOM Task Transport Protocol
Protocol Mode Description
UDP1 UDP with no “connection”; any input command responses, or any scheduled output
messages, will be sent to the IP address and port of the sender of the last received
UDP datagram.
UDP2 UDP with “pseudo session” (See the “UDP pseudo session”) description.)
TCP1 This connection operates as a normal TCP session with this exception: If there is a
Send error other than a re-transmission of a lost packet, the connection will be
terminated and the logical port will enter listen mode for a new connection. This can
occur if the remote client experiences a power or network interruption.
TCP2 TCP session with keep-alive timeout
An EVCOM session may be established for several reasons, such as for a StarUtil connection,
high-speed data logging, or an OEM application interface.
An active UDP session will be automatically re-established if the Sapphire unit is reset due to
power interruption. However, this is not possible for a TCP mode connection, except under
special conditions where the remote will be listening on the configured remote port. This
essentially reverses the server/client roles.
Client application messages scheduled on an ONTIME basis using the [OUTPUT] command
must be unscheduled prior to closing the connection; otherwise, the next user opening a
connection to that logical port (ETH1
– ETH4) receives the messages even if they are
unrequested or unwanted. Additionally, generating unwanted messages causes unnecessary
overhead on the GNSS board and consumes unnecessary bandwidth on the SPI bus sending
the messages to the Power IO board (where they are silently discarded until the next EVCOM
connection is established).Cancel all output messages when the connection is first established,
and then schedule only the necessary messages.
UDP1 mode operates in a connection-less manner. Because there is no authentication, and the
port never establishes a “connection,” a remote client does not know when that port is already in
use by another remote client. A connection attempt by a second client diverts any output stream
set up by a previous client to the second remote client. To prevent this, a remote client should
not use UDP1 mode.