1. Field of the Invention
The present invention relates generally to a system for providing peripheral device status information to workstations on a network.
2. Description of Related Art
In a typical networked multi-user computer environment, a number of individual workstations are linked together through a network, usually a local area network (LAN). Also linked on the LAN are one or more peripheral devices such as printers, facsimile machines, scanners or plotters. One or more file servers are also linked to the network and serve to manage allocation of the devices to workstations which request the use of the devices. The allocation procedures typically involve accepting requests, determining the address of the device requested, maintaining queues, establishing priorities and relaying data from the workstation to the device.
Typically when a workstation user wishes to determine the status of a device that is networked on a LAN, the method available depends upon the intelligence of the device. The earlier generation of peripherals were "unintelligent," or perhaps, better "uncommunicative." They accepted data from the LAN and processed it according to instructions, but were incapable of relaying status information back to the LAN. A workstation user, concerned about the status of a device to which he or she had sent a job, would have to leave the workstation to physically examine the device.
A server, such as a file server or a print server, might be able to provide some information regarding the status of a print job. However, this status information related to the status of the print job in a print queue, and the print queue was neither created, maintained nor serviced by the printer. If a print job was removed from the print queue, one could infer that the printer was handling the print job. However, the status of the print job as it was handled by the printer could not be ascertained. For example, absence of a print job from the print queue could mean that the print job was complete, or it could also mean that the printer had received the print job into its buffer and was still processing the print job.
More recently, peripheral devices such as printers have become available which are able to determine and relay information concerning their status through a communications port, such as a network interface card (NIC) or a printer (LPT) port. Thus, information concerning the printer's such as its device information (the manufacturer, command set and model of printer), the identity of the job it was currently processing, the status of its paper bins, ink supply, etc. which might be displayed on the printer's display panel, might be also relayed to a computer linked to the peripheral devices through a communications link. An example of this is the Lexmark Optra printer which provides identification data as well as other information as to status. However, querying the device and performing status checks slows the performance of the printer.
When numerous workstations are able to access an intelligent peripheral device through a network, the cumulative effect of their querying the peripheral device status repetitively is to significantly compromise the performance of the peripheral device. Such queries are also time consuming and make for inefficient use of network resources.
Furthermore, before the workstations can even access the peripheral devices, they typically perform a "discovery" operation. In performing discovery, a workstation searches the network for available peripheral devices. This discovery process can be quite burdensome to the network and can take a considerable amount of time. This burden is multiplied by the number of workstations on the network which perform discovery.
It is therefore an object of the invention to provide a system where workstations on a network can rapidly obtain information concerning the status of networked peripheral devices.
It is another object of the invention to provide a system where workstations on a network can rapidly obtain information concerning the status of networked peripheral devices without interfering with the performance of those peripheral devices.
It is still another object of the invention to provide a system wherein demand update of information concerning the status of networked peripheral devices is minimized so as to maintain device efficiency.