Logic Inputs
14-3
Acknowledgment: Sends OK
Errors:
Error Meaning
? err 1 wrong number of digits entered
? err 2 illegal digit entered
Default Condition: No Macros assigned
Examples:
Let’s assume that Logic Input 1 has been wired to an intrusion switch. The
opened switch contacts are in series between the logic input and ground.
When the switch is tripped, the logic input sees a high level. We want this
transition to cause the CW pitch to change. To accomplish this, you must
create a macro that changes the CW pitch to the desired value. Let’s assume
that a macro already exists to do this, and its name is 0050.
Now, you must enter the command to assign this macro to logic input 1’s low-
to-high transition. The command is:
(PW) 26 21 0050 *
Note: This is now a latched condition. That is, once the switch is tripped and
the CW pitch is changed, the pitch will stay at the new value until commanded
back to normal. This may be desirable, since the switch could have been
tripped late at night. You would need to keep the CW pitch changed until
acknowledged, not changed back to normal when the switch goes back to its
original state.
Other applications require that the condition not be latched. For example: A
115V relay could be wired with its coil to the 115VAC line at the repeater site. If
it has a SPST contact available, the contact could be wired in series between a
logic input and ground. When the relay is energized and the contact is closed,
the repeater is operating from AC power. When the relay is de-energized and
the contact is open, the repeater is operating from battery power. The contact
provides this information to the controller, which could append BAT (or a similar
message) to the repeater tail message. Users would know that they should limit
transmissions when they hear the BAT message. When AC power is restored,
the controller would automatically turn OFF the BAT message.
To program the above scenario requires two macros: one to program BAT into
the dropout message, and one to program (nothing) into the dropout message.
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