Registers - Tandy DCM-7 Operation Manual

Hayes protocol reference
When CO is entered, the transmitter is switched OFF and remains OFF until
Cl or reset command Z is entered. As long as the transmitter is OFF, the
Modem does not issue carrier even when it detects the answer modem's car"'
rier tone during originate mode operation .. For further information, refer
to Data line monitoring mode operation later. in this chapter.
H, h Hook switch control
Controls. the hook switch of a telephone. The HO setting is comparable to
the condition of the handset resting on the hook while the telephone line
is not in use. In the Hl setting, the handset is off the hook and the telephone
line is in use.. ·
Use the HO setting for normal operation. When originating or answering calls, ·
the Modem controls off hook condition automatically. ·
M, m Speaker Control
Controls the built-in speaker. Use Ml (defa:ult) to monitor a call in progress.
You can monitor signals on the telephone line such as a dial tone, ring-back
tone, busy signal and carrier tone. The speaker turns OFF when the Modem
recognizes a· carrier signal and sends a CONNECT result code.
When you want to continue monitoring the data communication, use M2
instead of M 1. Or, input MO if you do not want to use the speaker function
at all.
Registers
SO Defines the rings for answering a call
The value of register SO determines the number of times the phone will ring
before the Modem answers a call. Input any decimal number greater than
0 to set the Modem to auto:-answer mode.
If
the value is set
to
0, the Modem
will not answer a call.· Since the default value of SO is preset at 0, use the
prescribed syntax (refer to Command syntax, in Chapter 3) to change the
value when you use the Modem in auto-answer mode.
When DIP Switch 6 is OFF, the Modem will power-up in auto-answer mode
with SO= 1. Answer command A disregards the SO value since it enters an-
swer mode immediately.
Sl
Counts the rings
The value of Sl increases each time the phone rings and clears if no rings
occur within about 8 seconds of the last ring. This will operate only if the
· value of SO is greater than 0.
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