User's Guide

6.25.12
Transmit Inhibit
This feature allows you to stops all transmission including voice and data. The radio can receive
messages but not able to reply the acknowledgment request of the received message.
This feature is available for APCO 25 trunking, Type II trunking and Conventional operations for all
APX radios.
You can physically control the transmission of the radio especially during operation in hazardous
environments. An environment is considered hazardous if radio transmission could initiate an explosion
or other dangerous reactions.
6.25.12.1
Enabling Transmit Inhibition
Procedure:
Perform one of the following actions:
•
or to TxIn. Press the Menu Select button below TxIn.
• Turn off the ignition through Ignition Sense Line.
The display shows Tx inhibit on. You hear a sequence of short, low-high tones to indicate
that transmission is inhibited.
Pressing PTT triggers the radio sounds a constant short, low-pitched tone (reject tone).
NOTICE: The status of the Transmit Inhibit does not change after the radio powers up.
The softkey TxIn is created to ease the user of inhibition transmission besides relying solely on
Ignition Sense Line. Only if the Ignition Sense Line is on, the softkey TxIn works. If the Ignition
Sense Line is on, you can always turn on or off the Transmit Inhibition using the softkey TxIn;
but when the Ignition Sense Line is off, function of softkey TxIn is suspended, and the
Transmit Inhibition function is always off.
If PTT TX Inhibit is enabled, when using multi-control head with one active configuration, with the PTT
pressed on the active control head, any press on the programmable button of the other control head
which meant for that control head to be active control head causes an unstoppable long low-pitched
tone (Talk Prohibit Tone). The display shows Tx inhibit. This behavior can be stopped by pressing
PTT button again on the active control head
6.25.12.2
Disabling Transmit Inhibition
Procedure:
Perform one of the following actions:
•
or to TxIn. Press the Menu Select button below TxIn.
• Turn on the ignition through Ignition Sense Line.
The display shows Tx inhibit off. You hear a sequence of short, high-low tone (Transmit
Inhibit Off tone) to indicate that the transmission is back to normal operation.
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Chapter 6: Advanced Features
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