PJL-Compatible Print Device
When communicating with HP's Printer Job Language (PJL) compatible print device (such as an HP LaserJet IIISi or HP4-series print device) the printer driver embeds a PJL command in the data stream that causes the print device to send a signal back to the print server. The signal notifies the server when the page has finished printing. If the print device understands PJL, bi-directional printing communication over the network is possible (HPMON must be used in Windows NT). If your print device does not recognize PJL, you must create a print monitor for Windows NT that can accept a signal sent from the print device.
Most network protocols support bi-directional printing. Networks protocols such as the AppleTalk protocol and Data Link Control (DLC) protocol can provide bi-directional communication in Windows NT. Although TCP/IP can carry the signal, the Line Printer Remote (LPR) specification has no facility for this signal. Therefore, the Windows NT TCP/IP protocol does not support network bi-directional printing.
One of the Windows NT Print Monitors, HPMON, supports bi-directional printing over the network. HPMON uses one of its features called "Advanced Job Status" for detecting a response signal sent from the print device. This feature is disabled by default. To enable this feature:
- From the Print Manager Printer menu, choose Properties.
- Choose Settings.
- Choose Port.
- Select the Advanced Job Status check box.
- Quit Print Manager.
NOTE: When the HPMON is active, print jobs are not removed from the print queue unless the print device understands PJL. If the print device does not respond with a signal to the print server, HPMON informs Print Manager that the print job is not complete.