Transport; Messaging; Message Root - Printronix SL4M Reference Manual

This following sets up PXML using the Ethernet port on port number 3007:
!PTX_SETUP
CONFIG-MPI_SELECT;PXML
CONFIG-PXML_PORT;ETHERNET
CONFIG-PXML_PORT_NUM;3007
PTX_END

Transport

The printer provides a TCP server socket that can be opened by a client as a
telnet session. Only one socket is allowed to be open at a time. The factory
default is port 3001 for PNE protocol and 3007 for PXML protocol.
The client is responsible for opening and maintaining the session. The
connection could be broken at any time, either by a network error or by the
printer being powered down. The client must detect that the connection is
broken and reconnect to the port. Most TCP stacks do not immediately report
that the connection is down, so the client must 'ping' the printer on a regular
basis.
No separate framing protocol is provided, so the client must continuously
parse the incoming data stream for XML messages. The client may send XML
messages at any time.

Messaging

All messages are in XML format and are described by a formal XML schema.
Command messages are messages that are sent by the client to perform
some action or request information.
Response messages are messages that are sent by the printer, either as a
response to a command message or as an unsolicited message that is
triggered by a change of printer state or an event that occurs during a print
job.
All responses are not synchronized. When a command asks for a response, it
adds a request to an event queue. A reply to a command may be interspersed
with unsolicited messages, although all messages are guaranteed to be well
formed XML.
To protect the printer against unauthorized use, commands that affect printer
operation require a password to be embedded in the message. This password
is the same as the printer's 'telnet' root password.

Message Root

All PXML messages are wrapped with a common root element, named pxml.
The standard XML header <?xml version="1.0"?> must be sent at the
beginning of each message so that the XML parser can discard faulty
messages.
Message Root
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