---
name: "faxmodem"
section: "8"
platform: "linux"
package: "hylafax-server"
version: "3:6.0.7-11.1"
release: "Debian 13 (Trixie)"
platforms: ["linux"]
url: "https://new.carta.tech/faxmodem"
---

# faxmodem(8)

dynamically add a modem to a HylaFAX server system

## NAME

faxmodem - dynamically add a modem to a *HylaFAX* server system

## SYNOPSIS

**/usr/sbin/faxmodem** \[ **-q** *queue-dir* \] \[ **-c** *capabilities* \] \[ **-p** \] \[ **-P** \] \[ **-u** *priority* \] *modem*

## DESCRIPTION

*faxmodem* sends a message to the *HylaFAX* queuer process [*faxq*(8)](/faxq/8.md) telling it that the specified modem is ready for use and informing it about its fax-related capabilities. This is the mechanism by which modems are added in a send-only configuration. Once a modem has been configured its status can be reconfigured using the [*faxstate*(8)](/faxstate/8.md) program. *faxmodem* can also be used to alter the capabilities and usage priority of a previously configured modem.

The specified *modem* is either the terminal device name where the modem is attached or a *HylaFAX* device identifier (see [*hylafax-config*(5)](/hylafax-config/5.md) for information on device identifiers). Device names may be given without a leading directory pathname; e.g. ttyf2 instead of /dev/ttyf2.

To figure out the capabilities of a modem either use the [*probemodem*(8)](/probemodem/8.md) script or manually communicate with the modem. For a Class 2 modem the capabilities are given in the response to the \`\`AT+FDCC=?'' query command and for a Class 2.0 modem the \`\`AT+FCC=?'' command. To check if a modem is capable of polled retrieval of documents use \`\`AT+FSP=?'' for a Class 2.0 modem or \`\`AT+FSPL=?'' for a Class 2 modem; if \`\`1'' is indicated in the response then the modem supports polling. For example,

```
hyla% cu -l ttyf2
Connected
at+fclass=2.0
OK
at+fcc=?
(0,1),(0-5),(0-2),(0-2),0,0,0,(0-7)
OK
at+fsp=?
(0,1)
OK
```

In this case the modem would be added using the command:

```
/usr/sbin/faxmodem -c '(0,1),(0-5),(0-2),(0-2),0,0,0,(0-7)' ttyf2
```

(by default polling is assumed to be supported).

Class 1 modems require a different technique. The host implements most of the fax protocol so all that is needed is to identify the possible signalling rates the modem supports for transmitting; this is done with the \`\`AT+FTM=?'' command. For example,

```
hyla% cu -l ttyf2
Connected
at+fclass=1
OK
at+ftm=?
24,48,72,73,74,96,97,98,121,122,145,146
OK
```

In this case the modem supports 2400, 4800, 7200, 9600, 12200, and 14400 bps signalling rates so the modem would be added using:

```

/usr/sbin/faxmodem -c '(0,1),(0-5),(0-2),(0-2),(0,1),0,0,(0-7)' ttyf2
```

## OPTIONS

The following options are available:

- **-c**

  Specify the fax capabilities using the syntax defined by the \`\`Class 2'' specification: \`\`(*vr*),(*br*),(*wd*),(*ln*),(*df*),(*ec*),(*bf*),(*st*)''. where, *vr* specifies vertical resolution, *br* specifies bit rate, *wd* specifies page width, *ln* specifies page length, *df* specifies data compression, *ec* specifies error correction, *bf* specifies binary file transfer, and *st* specifies scan time/line; and each of the above specifications is a range or list of numbers that defines the exact capabilities of the modem. For example, the default capabilities are \`\`(0,1),(0-3),(0-4),(0-2),(0),(0),(0),(0-7)'' which specifies the modem is capable of sending and receiving both low and high resolution facsimile with a variety of page sizes; supports signalling rates 0-3 (2400 bps through 9600 bps); supports only 1D-encoded data compression; and does not support error correction or binary file transfer. A modem's ability to support polled retrieval of facsimile is specified separately with the **-p** and **-P** options.

- **-p**

  Specify the modem is **not** capable of polling for remote documents.

- **-P**

  Specify the modem is capable of polling for remote documents (default).

- **-q** *dir*

  Use a spooling area other than */var/spool/hylafax*.

- **-u** *priority*

  Assign the specified priority to the modem when scheduling it for outbound use. Modem priorities are numbers in the range \[0..255\] with lower numbers meaning higher priority. Modems are initially assigned priority 255.

## FILES

```
/var/spool/hylafax	default spooling area
/var/spool/hylafax/FIFO	fifo for contacting faxq
```

Consult [*hylafax-server*(5)](/hylafax-server/5.md) for a complete discussion of the structure and content of the spooling area.

## SEE ALSO

[*hylafax-server*(5)](/hylafax-server/5.md), [*faxgetty*(8)](/faxgetty/8.md), [*faxq*(8)](/faxq/8.md).