Xerox PHASER 6121MFP - Fax Troubleshooting; Fax Protocol Report

Phaser 6121MFP Service Manual 4-11
General Troubleshooting
Fax Troubleshooting
If the Fax isn’t operating correctly, try using the copy function. If the copy
function’s printing results are correct, the probability of a fault in the Fax itself is
low. The fault is likely in the telephone line or receiving Fax. If the fault is in the
telephone line, first retry sending the data. If there is no improvement, contact the
telephone company. If the copy function’s printing results are incorrect,
troubleshoot the printer to correct the problem.
Fax Protocol Report
The Protocol Report provides transmission results, timing, and communications
activity information about each Fax transmission. The Protocol Report provides a
detailed log of the communications activity between devices. Use this report to
diagnose possible communications errors between machines.
Enabling the Protocol Report
To set the desired behavior of the Protocol Report:
1. At the initial screen on the Control Panel, press OK > Stop/Reset > 0 > 0 >
Stop/Reset > 0 > 1.
2. Select Service’s Choice and press OK.
3. Select Protocol Report and press OK.
4. Set the desired setting:
• Off: Disable the T.30 communication report.
• On: Print a T.30 communication report after every Fax transmission.
• On Error: Print a T.30 communication report only when an error occurs.
Common Fax Transfer Commands
The most common commands exchanged between Fax machines during a typical
transfer of data are listed in the following table. When reviewing the Protocol
Report, trace the exchange of commands to identify irregularities. Commands in
parentheses (_) may or may not appear in the log.
Command Definition Appropriate Responses
(NSF) (CSI) DIS Negotiating capabilities from
a manual receiver or an auto
answer terminal.
(NSC) (CIG) DTC
(TSI) DCS
(NSF) (CSI) DIS
(CRP) (TSI) (NSS)
(PWD) (SEP) (CIG) DTC
(PWD) (SUB) (TSI) DCS
(NSC) (CIG) DTC
(PWD) (SEP) (CIG)
DTC
Mode setting from calling
terminal.
This is a poll operation.
(TSI) DCS
(NSF) (CSI) DIS
(CRP) (TSI) (NSS)