Use special characters in the number your modem dials on Mac
You can include special characters, known as dialing modifiers, in the phone number your modem dials. Dialing modifiers change the way the number is dialed. For example, inserting a comma (,) in a phone number inserts a 1-second pause between the numbers. This might be useful if you’re calling from a phone line that requires you to dial a number for an outside line. Inserting a pause gives the phone enough time to establish a connection with an outside line.
, (dial pause): The modem pauses for 1 second before dialing the number following the comma. You can add additional commas if you need a longer pause.
@ (wait for silence): The modem waits for at least 5 seconds of silence before continuing. For example, if the number is 1234567@8888, the modem dials 1234567, waits for the call to be answered, then dials 8888.
^ (enable calling tones): This modifier enables calling tones for the number being dialed. By default, calling tones are disabled for internal 56K modems sold in North America. You might want to enable calling tones if the device you are calling uses calling tones to differentiate between a voice, fax, or data call.
W (wait for dial tone): The modem waits for a dial tone before dialing numbers following a W. If a dial tone is not detected after a specified time, the modem gives up and doesn’t place the call.