Service manual

OPERATION
3-13
April 2001
Part No. 001-9800-203
for .25, .50, .75 or 1.0 second, and the cycles are
programmable for 1-8. Horn alert installation is
described in Section 2.4.
Operation in Modes A and B
The horn alert is programmed to operate in Mode
A or Mode B (descriptions follow). The on or off
condition that is automatically selected by these modes
can be changed using the HRN ALRT menu parameter
(high tier models only) or an option switch
programmed for the horn function (see Section 3.5.1).
For example, when power is turned on in Mode B, the
horn alert automatically turns off. It could then be
enabled by pressing the option switch.
A “power-off delay” can be PC programmed to
occur when power is turned off by the ignition switch
(see Section 3.5.12). The horn alert can then remain
active for a time after the ignition is turned off. If the
ignition switch does not control transceiver power,
only the front panel power switch affects operation in
the following modes.
Mode A (Manual On/Off)
The current horn alert mode does not change
when power is turned on or off by either the ignition
switch or power switch. Therefore, the horn alert is
totally controlled by the option switch or menu
parameter.
Mode B (Automatic On/Off)
Ignition Switch
- The horn alert always turns off when
the ignition switch is turned on, and always turns on
when the ignition switch is turned off (if there is a
power-off delay programmed).
Power Switch
- The horn alert is always off when the
power switch is turned on.
NOTE: The preceding automatic operation overrides
an on or off condition that may have been selected by
the menu mode or option switch.
Permanently Enabling Horn Alert
If neither an option switch nor menu parameter is
programmed, this feature can be permanently enabled
by programming the horn alert default to “ON”.
Operation in each mode is then as follows:
Mode A - If the horn alert is to be always enabled, this
mode could be used.
Mode B - This mode could be used if the ignition
switch controls power. The horn alert is then always
disabled when the ignition switch is on and always
enabled during the turn-off delay when it is off. If the
ignition switch does not control power, this mode
cannot be used because the horn alert turns off the first
time power is turned on and there is then no way to
turn it back on.
NOTE: A programmed default condition remains in
effect only until the first time it is manually or auto-
matically changed.
3.5.11 OPTION SELECT
A programmable option switch (see Section
3.5.1) or the OPTION menu parameter (see Section
3.6.16) can be used to control some type of dealer-
defined accessory such as a DTMF decoder. When the
switch is used, the enabled condition is indicated by
the decimal point for the switch (low tier models) or
in the display (high tier models).
If this function is used, the I/O line controlling
the option (such as the Output D line of accessory
connector J101) must be programmed for the Acces-
sory Option as described in Section 4.9. These are
CMOS outputs with a 470-ohm series resistance and a
typical maximum source and sink current of 2 mA.
Therefore, some type of driver circuit may be required.
3.5.12 POWER TURN-OFF DELAY
The transceiver can be installed so that the
vehicle ignition switch as well as the front-panel
power switch controls transceiver power. This is done
by installing the ignition switch cable and removing
R170 on the audio/logic board (see Section 2.4.3).
Turn-off delays of Immediate, 10, 20, 30, 40, or 50
minutes, 1, 2, 4, 8, 10, 12, or 16 hours or Forever can
then be programmed. The delay can be overridden at
any time by turning power off using the front-panel
power switch or turning the ignition switch back on.