hpoj reference: ptal-connect and ptal-print

Syntax

	ptal-connect [devname] action [options...]
	ptal-print [devname] [options...]

• devname is the optional PTAL device name
• action specifies the remote service and is one of:
  • -print -- the print service (the default for ptal-print)
  • -scan -- the scan service
  • -socket socketID -- a particular remote socket ID
  • -service serviceName -- a particular remote service name
• options... is zero or more of:
  • -eoftimeout seconds -- Idle timeout before exiting after an end-of-file condition is encountered on standard input
  • -fwdlen maxForwardDatalen -- Forward data packet size requested to be negotiated with the device
  • -revlen maxReverseDatalen -- Reverse data packet size requested to be negotiated with the device
  • -retrycount seconds -- Maximum number of times to retry a failed connection (default is 10)
  • -noretry -- Disables retries of failed connections (same as "-retrycount 0")
  • -infretry -- Retries failed connections forever (same as "-retrycount -1")
  • -retrydelay seconds -- Delay between each retry (default is 1)
  • -quiet -- Disables "connecting" message
  • -uel, -nouel -- Enables/disables print job boundary escape sequences (default is disabled)
  • -dump -- Dumps data structures (for debugging)

Notes

-print is used by ptal-cups (the PTAL CUPS backend) to pass printer-ready data to the device.

"-service ECHO" is useful for verifying basic device connectivity, because text you send in the forward direction is echoed in the reverse direction. (However, this service may not work properly on the OfficeJet LX and 300 series.)

-scan only connects to the scan service on the device and doesn't in an of itself start a scan operation; use libsane-hpoj for that. It is not recommended to call "ptal-connect -scan" directly, because in certain cases it may make the scan service unusable for subsequent actual scans (due to improper negotiated packet sizes) until the device is power-cycled or ptal-mlcd is restarted.

ptal-mlcd supports several "virtual" services which do not involve the device in any way.

Most if not all devices have a limit of one connection to each service at any given time. Subsequent connections will fail.

The "datalen" parameters to -fwdlen and -revlen do not include the 6-byte header inherent in the MLC and 1284.4 protocols. The requested sizes are not guaranteed to be honored, because the device is permitted to reduce either or both sizes. For MLC mode, the negotiated packet sizes for a given service are fixed after the first negotiation, and subsequent requests are ignored. For 1284.4 mode, different sizes may be honored each time. Some combinations of sizes may have erroneous results on some models.

Specifying -infretry causes failed connection attempts to be retried indefinitely, even in situations where the connection would never be successful. Other (non-negative) retry options may cause fewer retries than expected, depending on the nature of the connection failure.

If you're connecting through an HP JetDirect print server (i.e. with a PTAL device name prefix of hpjd:), then the following limitations apply:

• -scan, -socket, and -service require a JetDirect model with multi-function peripheral support:
  • Parallel-port JetDirects: 70X, 170X, 300X, or 500X only
  • USB JetDirects: 175X and probably later models
• -scan requires firmware x.07.xx or later.
• -socket and -service require firmware x.08.xx or later.
• For parallel-port JetDirects, -socket and -service are only supported for devices running in 1284.4 (not MLC) mode. For USB JetDirects, they are supported in both modes.
• A limited number of clients may have -socket and -service connections to the same device at any given time, even if they are to different services.
• -fwdlen and -revlen requests are ignored.