Xerox WorkCentre Pro 412 Service Manual

Also see for WorkCentre Pro 412: Quick start guide Product safety data sheet Service manual Quick start guide User guide

Contents

Xerox WorkCentre Pro 412 Service Manual Manual pdf 48 page image

Circuit DescriptionWorkCentre Pro 412Launch Issue5-22 August 20015-4 Host InterfaceReferred to IEEE 1284 standard.5-4-1. Host InterfacePARALLEL PORT INTERFACE PART KS32C61200 enables the parallel interface with the PC. This part isconnected to the PC through a Centronics connector. It generates major control signals that are used to actu-ate parallel communication. It is comprised of/ERROR, PE, BUSY, /ACK, SLCT, /INIT, /SLCTIN, /AUTOFDand /STB. This part and the PC data transmission method support the method specified in IEEE P1283Parallel Port Standard (http://www.fapo.com/ieee1284.html). In other words, it supports both compatibilitymode (basic print data transmitting method), the nibble mode (4bit data; supports data uploading to PC) andECP (enhanced capabilities port: 8bits data - high speed two-way data transmission with PC). Compatibilitymode is generally referred to as the Centronics mode and this is the protocol used by most PCs to transmitdata to the printer. ECP mode is an improved protocol for the communication between PC and peripheralssuch as printer and scanner, and it provides high speed two-way data communication. ECP mode providestwo cycles in the two-way data transmission; data cycle and command cycle. The command cycle has two for-mats; Run-Length Count and Channel Addressing. RLE (Run-Length Count) has high compression rate (64x)and it allows real-time data compression that it is useful for the printer and scanner that need to transmit largeraster images . Channel Addressing was designed to address multiple devices with single structure. Forexample, like this system, when the fax/printer/scanner have one structure, the parallel port can be used forother purposes while the printer image is being processed.This system uses RLE for high speed data trans-mission. PC control signals and data send/receive tasks such as PC data printing, high speed uploading ofscanned data to PC, upload/download of the fax data to send or receive and monitoring the system controlsignal and overall system from PC are all processed through this part.Compatibility Hardware Handshaking Timing