Troubleshooting
Problem
This document outlines the steps to take to turn Error Correction Mode (ECM) on for Facsimile Support.
Resolving The Problem
Error Correction Mode (ECM) helps with fax transmissions, especially those that have line noise on the analog phone line. It forces fax machines to handshake after every 256 frames of data and step down to lower baud rates, if necessary.
Note: The receiving fax machine must also support ECM.
The ECM setting is on the Add Fax Card (ADDFAXCRD) command. There is not a way to update the current fax card configuration so it is necessary to remove the fax card using the Remove Fax Card (RMVFAXCRD) command and re-add it using the ADDFAXCRD command.
NOTE: Typically, the fax controller is FAXD01, however it can be named differently and there may be more than one. If you're not sure of the fax controller name(s), use the PRTFAXCFG command to generate a spooled file with the names of the fax controller(s).
Do the following:
| 1. | End Facsimile Support: ENDFAXSPT FAXD(*ALL) NOTE: This will end Enhanced Services too, if started Verify that the QFAXSBS and QFQSBS subsystems end by using WRKSBS |
| 2. | Use the Print Fax Configuration (PRTFAXCFG) command to generate a spooled file with the current configuration information. Note: The output from the PRTFAXCFG command does not show if a prefix telephone number had been configured. Use the DSPPFM FILE(QUSRSYS/QAFFCFG) MBR(FaxControllerName) command to view the current fax configuration. Column 100 on the third line identifies the prefix number if it was configured. For more information, refer to the following document Determining if the Fax Card Is Auto-Dialing a Prefix |
| 3. | Remove the fax card: RMVFAXCRD FAXD(FaxControllerName) FAXCRD(FAX1) Note: The FAXCRD will always be FAX1 |
| 4. | Add the fax card, setting the Error Correction Mode parameter to *ON. IMPORTANT: Use the information collected with PRTFAXCFG and DSPPFM to determine the other values to use, such as prefix number, TSI, etc. ADDFAXCRD FAXD(FaxControllerName) ECM(*ON) |
| 5. | Repeat Steps 3 and 4 for each controller with a fax card that should be changed. |
| 6. | Start Facsimile Support: STRFAXSPT FAXD(FaxControllerName) F4=Prompt on the STRFAXSPT command to specify additional controllers, if needed |
For more information on the QAFFCFG file: Configuration File (QAFFCFG) Information
Historical Number
30924318
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Document Information
Modified date:
13 March 2026
UID
nas8N1019281