Table of Contents
Advertisement
ECM
Error Correction Mode
Encoding
The data of your fax transmission are encoded and compressed for the transmission. The
minimum standard is MH (Modified Huffmann). Better encoding methods are MR (Modified
Read) or MMR (Modified Modified Read).
Energy Saving Mode
The device is normally in the energy save mode. Whenever you receive a fax or if you would
like to print or make a copy, your device will automatically switch back into operating mode
(see Warm-Up Phase).
Error Correction Mode (ECM)
The ECM method reduces transmission errors that result, for example, from bad telephone
lines, thereby reducing the duration of transmissions. Both of the connected fax machines
must support ECM.
Fax Groups
Fax machines are classified in terms of internationally standardised fax groups based on
their transfer type and speed. Connections between two devices of different groups is possi-
ble; the lowest common transfer rate is selected. The determination of the speed takes place
during the handshake (see Handshake). Fax groups 1 to 3 are analogue fax machines. Now-
adays, groups 1 and 2 are hardly to be found any longer; fax machines of group 3—which
have a transfer speed that ranges from 9,600 to 33,600¦bps—are currently most standard.
Group 4 fax machines are digital devices that function exclusively on ISDN systems. They
have a maximum transfer speed of 64,000¦bps.
Fax Polling
With active fax polling, one can retrieve a document from another fax machine. For fax poll-
ing from a larger company offering several polling services, you can also enter sub-addresses
/ direct-dial numbers. In order to do this, you must insert a dialling pause between the fax
number and the sub-address (see Dialling Pause).
Fax Signal, CNG Tone (= Calling Signal)
The tone that a fax machine sends out to announce a fax transmission. When the CNG tone
occurs, the fax switch of the device recognises an incoming fax call and starts the fax recep-
tion.
Fax Switch
The fax switch checks incoming telephone calls and controls the ringing behaviour of the fax
machine. According to the selected mode, fax transmissions will be received either automat-
ically or manually.
Glossary · ECM ¦ 79
Advertisement
Table of Contents
