Filter
Top Products
130
DataTalker Owner’s Manual
F.3 Dial Modifier Commands
Pulse or Tone Dial P T
The MMH2834 dials numbers using either pulse or tone dialing, or a combination of both
methods. Pulse dialing is a method used by rotary-dial telephones, which involves the timed
opening and closing of line relay.
Tone dialing is the method used by pushbutton (touch tone) telephones, and is sometimes
referred to as DTMF, or Dual-Tone Multi-Frequency dialing.
The method used is selected by including a P for Pulse or a T for Tone in the dialing command,
right before the digits you wish to have dialed in that manner.
For example, you would pulse-dial the number 555-1212 by entering ATDP5551212 and hitting
RETURN. You could tone-dial the same number by entering ATDT5551212 and hitting RETURN.
If neither Pulse nor Tone dialing is specified in the dial command, the MMH2834 uses whatever
method used last. If the modem has been reset or just powered up, it uses Pulse dialing, even if
the letter P is not included in your dial command.
Nearly all telephone systems in the U.S. are now compatible with tone dialing. Since that is the
faster method, you will probably choose the tone method for your dialing.
An example of combining pulse and tone dialing could involve a PBX system where 9 had to be
pulse-dialed first, then the rest of the number tone-dialed after pausing for a second dial tone.
The number would be dialed by entering ATDP9, T5551212 and RETURN. (The comma causes
a pause, which we’ll explain soon.)
Set Pulse Dial Ratios &P
This command sets the time ratios between the open and closed portions of the dialing pulse
frequencies. To set the dialing pulse ratio of 60 ms to 40 ms, enter AT&P0. To set a ratio of 67
ms to 33 ms, enter AT&P1. The factory default is &P0.
Automatic Pauses in Dialing ,
You can cause the MMH2834 to pause during the dialing sequence by entering a comma
character where the pause is desired. This pause will last two seconds. If a longer pause is
desired, more than one comma may be entered consecutively, with each comma causing a two
second pause. You also have the option of changing the length of the pause caused by the
comma, from two seconds to any other value from 0 up to 255 seconds. This is done by setting
register S8 (see Appendix E). Each comma in a dialing command counts as one of the sixty
allowed characters.
Long Space Disconnect Y
When two modems are connected in Normal mode (i.e., without error correction) there is no
"polite" means of requesting a disconnect. A link disconnect request packet is sent under reliable
connections. As a result some "garbage" may be received when a hangup command is issued.
The Y1 command enables the modem to use the break signal which accomplishes the hangup as
an instruction to shut off its receiver and disconnect (both modems must have Y1 enabled for
this feature to be effective). Y0 (factory default) disables this function.