CHAPTER 5: Command Mode

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 select a dialing pulse ratio of 60 mSec/40 mSec, enter AT&P0. To select a ratio of 67 mSec/

33 mSec, enter AT&P1. The factory default is &P0.

Automatic Pauses in Dialing ,

You can cause the Series II Modem to pause during the dialing sequence by entering a comma character where the pause is desired. This pause lasts 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 S-Register S8 (refer to Chapter 6). 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 (that is, 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 hang-up command is issued. The Y1 command enables the modem to use the break signal which accomplishes the hang-up 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.

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Black Box MD1640A, MD1641A manual Set Pulse Dial Ratios &P, Automatic Pauses in Dialing, Long Space Disconnect Y