HP LaserJet 5p/mp Service Manual - Page 123

HP LaserJet 5P/5MP, 6P/6MP Printer Service Supplement New Product Features The LAP and LMP layers can reside in either firmware, software, or a combination of both. There are different LAP and LMP protocols for primary and secondary devices. The HP LaserJet 5P/5MP and 6P/6MP printers have the complete secondary protocol, and any host trying to communicate via the infrared (IR) port must have the complete primary protocol installed. The primary protocol software is the responsibility of the host supplier. It is not provided by Hewlett-Packard Company with the printer. IrDA communications can be obtained either via an internal IR port or an external IR accessory. Several manufacturers offer complete accessory upgrades for both host and peripheral devices. primary device Application GDI DDI Ptr DVR IRLMP IRLAP IR Physical Transmitter ASCII Data Windows System Standard Windows LJ Printer Driver (SW) IR Redirector (Software) IR Driver Packetizes Data (SW or FW) Protocol Serializer IR Chip Data Packets & Queries Receiver Responses Formatter I/O Buffer IRLMP IRLAP IR Physical Receiver secondary device ASCII to Raster Data ASCII Data Buffer Unpacks Data Checks Packets Protocol Deserializer IR Chip Transmitter Figure 8. IR Data Flow. 20