There is not “standard” number of rings to set your fax machine to answer the phone. Usually, a fax machine is set to pick up anywhere between one and six rings. Some people configure their fax machine not answer at all, and answer fax calls manually.
Technologies you can use to manage ring challenges
Online fax service – a virtual fax machine that is accessed over the internet. It can replace both a fax machine and fax line in a home or office.
DRPD (distinctive ring pattern detection) – A fax feature that can detect a distinctive ring (one phone line can have two phone numbers assigned to it, each with a distinctive ring) and answer only on select rings.
TAM – a switch that can tell if an incoming call is a voice or fax call, and can route the call to the appropriate device. It only works with answering machines, not voicemail. Some fax machines are equipped with both a TAM and an answering machine.
Reasons for fewer rings
If the fax machine has its own dedicated fax line shared with nothing else, a short number of rings (1-2) can be preferable. This way the fax is received quicker, and there is less noise created from ringing.
If the fax machine is on a shared phone line with multiple numbers and DRPD (distinctive ring pattern detection), fewer rings can also help for the same reason.
Reasons for more rings
If the fax machine shares a phone line with regular phone line use, some people prefer to set their fax machine to answer after lots of rings (as many as six).
Lots of rings help to give you more time to get to the phone if it rings.
Reasons for no rings (manually answer the fax)
Some people simply prefer to have a fax machine connected and only manually answer the fax when it comes through. These users rarely use fax, and only receive one when they’re expecting it.
This can be the simplest answer for a shared landline with only one phone number assigned to it. Any time the line rings, voicemail or an answering machine will eventually answer if a person does not.
The challenge with this approach is that if there is nobody home the fax will not be received. There may be times when you are literally waiting around the house to receive your fax.
A note on shared lines
One of the biggest challenges with fax is the use of a shared line. When people have fax as well as other features such as voicemail, an answering machine, a modem, and an alarm system on the same line there can be a challenge with the number of rings.
Voicemail and fax can’t work together if both are answering the line automatically. Whichever is set to answer on the fewer number of rings will always answer the line. A fax cannot hand the line over to voicemail, as voicemail is a centralized application that cannot be reached once the line is answered (which a fax machine needs to do to see if the call is a fax). Once voicemail has answered the call, it cannot hand the call back to the local phone.
An answering machine and fax can work together. To do so they will need to employ a TAM device that can check the line and hand the signal off to the appropriate device.
Modems and alarm systems can coexist with a fax machine, but only one device can automatically answer the line.