Xerox Phaser 6128 MFP, Руководство по обслуживанию

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Phaser 6128MFP Service Manual 2-63
Theory of Operation
When the image data has been successfully received, the receiving side sends out
Message Confirmation (MCF) to prompt for subsequent image data transmission.
When the received image data contains permissible errors, the receiving data side
responds with Retrain Positive (RTP). When unacceptable errors are detected, the
receiving side responds with Retrain Negative (RTN).
To a signal requesting operator intervention, the receiving side responds with
Procedural Interrupt Positive (PIP) when the image data has been received
successfully. When the image data contains unacceptable errors, the receiving side
responds with Procedural Interrupt Negative (PIN). When retransmission is
required in Error Correction Mode (ECM), the receiving side responds with Partial
Page Request (PPR).
• ECM – A transmission method that manages the encoded data by dividing it
in units called frames and by numbering them. In the event of image
corruption due to noise, etc., image quality can be corrected by retransmitting
only the corrupted units specified by number. Multiple frames form a unit
called block. One block transmitted, or multiple frames retransmitted are
called partial page. To use ECM, both the sending the receiving sides must
have ECM feature.
• Phase E – Call Release
This phase terminates the entire fax session and releases the line. Before
releasing the line, the sending side sends out Disconnect (DCN), which expects
no response.
Overview of Protocol Monitor
Protocol Monitor allows the user to monitor and print the transmission/reception
records of signals during a G3 fax session that is in conformance to the ITU-T
Recommendation T.30, thereby helping to isolate fax communication issues.
Phase A
Phase B
Phase C
Phase E
Phase D
EOP MPS EOM
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