The first few items displayed on this pane have to do with the channels used by the device. The number of available channels, usable channels, and the maximum channels to use for sending and receiving are all listed.
This option designates the highest supported compression that this device can use when sending and receiving faxes.
Receive baud rate
This is the maximum rate in bits per second (bps) at which faxes can be received by the fax device.
Send baud rate
This is the maximum rate in bits per second (bps) at which faxes can be sent by the fax device.
Enable Error Correcting Mode (ECM)
Click this check box to enable Error Correcting Mode (ECM). Receiving devices that support ECM can request that portions of an image be resent if they are received with errors. This is enabled by default for most fax devices.
Use Black Ice engine
Check this box if you wish to use the Black Ice fax engine with this device instead of RelayFax's native engine. Depending on the device you are using, this option may or may not be available. Some older device architectures may require you to use the Black Ice engine.
If you are using a distinctive ring system, you can use these options to designate the RING patterns to which the fax device will respond. If in incoming call returns a ring code that is disabled here, RelayFax will ignore that call (i.e. the fax device will not answer it).
Use this option to designate whether or not the modem's speaker will be activated when the modem is in use. You can choose to leave the speaker Off or On, or you can set it to be activated only Until Connected. The latter option will cause the speaker to be activated only until the modem successfully establishes a connection (for example, while dialing and attempting to connect to a fax number).
Use this option to designate the desired volume of your modem's speaker.
Enable DTMF detection
If your device supports voice features, click this option to configure it to listen for DTMF (Duel Tone Multi-frequency, also known as "Touch Tone") signals when answering calls. Any DTMF digits received will be treated as Direct Inward Dialing (DID) by RelayFax for the purpose of routing incoming faxes. RelayFax also is equipped with DTMF support for CAPI devices. As with DTMF support for voice modems, the DTMF digits will be used as DID, but only if no called party number is received. Otherwise, the DTMF digits will be added to the fax number, separated by "x", and that combination will be treated as DID. In that case an account's DID setting would have to look something like, "1234567x1234" in order for the fax to be routed properly.
When using the Black Ice engine, you must specify the number of DTMF digits to listen for on the Modem Properties dialog. When using the Alt-N fax engine or CAPI devices, instead of specifying the number of digits, the line will be monitored for ten seconds or until a fax tone is received. You can adjust the timeout value by editing the VoiceAnswerTimeout parameter located under the [FaxServer] section of the RelayFax.ini file.
To send DTMF digits with voice modems or CAPI devices, use the "x" or "@" character to separate the fax number from the DTMF digits. For example, "FAXNUMBER:1234567@1234" will dial "1234567" and wait for silence (lack of ringback), transmit the DTMF digits "1234", and then start the fax transmission. Using "x" instead of "@" allows for the format: "firstname.lastname@example.org". Note, however, that although RelayFax displays DTMF digits after "x", it actually sends "@" to the modem. The modem-specific parameters of the "@" character should be documented in your modem's manual under the "D" command. For CAPI devices, there are several DTMF options in the [CAPI] section of RelayFax.ini to control the delay before and after sending DTMF digits, the length of each digit, and the gap between digits in milliseconds.