In the context of fax machines and phones, ‘tam’ stands for ‘telephone answering machine.’
It is used on a phone line with multiple answering mechanisms – such as a fax machine and an answering machine.
The TAM function allows the call to be routed to the answering machine or the fax machine depending on whether not the call is a fax.
TAM on a fax machine
Some fax machines have a ‘tam’ feature – it means that when they answer a ringing line if the call is a fax it will start receiving a fax.
If the call is not a fax, however, then the call will be answered by the fax machine’s answering machine, or by an answering machine plugged into the extension of the fax machine.
TAM as a standalone unit
A TAM can act as a standalone unit that sits ahead of a fax machine and answering machine.
With a standalone unit, there are special ports that the fax machine and answering machine are plugged into. Some models may allow for modems or an extra phone line.
With a standalone unit, a best practice is to set the number of rings on the fax machine to one or two more than than the TAM is set to answer for.
When the TAM receives the call, it checks whether it is a fax while it keeps the fax machine ringing. If the call is a fax, then it lets the fax machine pick up the call, otherwise it disconnects the fax machine.
As the TAM temporarily answers a call to see if it is a fax or not, callers can experience a temporary delay in the call while the TAM is checking to see if is a fax or not. To someone voice calling the line, it may sound like the call has dropped while the line is being checked.
Voicemail will not work with TAM.
Compared with an answering machine (that connects to the phone line in the home or office), voicemail is a service run by the phone company.
For the TAM to work it needs to temporarily answer the phone call to understand if the call is a fax or not.
If the call is answered and found not to be a fax call, the TAM would disconnect the fax machine, however the phone company would consider the call to be answered, and the phone company’s voicemail would not answer the call.
HP All-in-One or Fax Product – Using the Product with a Telephone Answering Machine (TAM) – the most complete guide we’ve found to setting a fax machine up with a TAM service.