Simplex conversation (Event Handler)

General

This article describes how you can override the voice-operated duplex (VOX), and have a fixed speech direction. Two applications are described.<br\> The first one describes how calls from a master station can be programmed to have initial speech direction from the called station towards the master station.<br\> The second one describes how the whole exchange can be set in permanent simplex mode.<br\> Software requirement: AMC 08.20 or newer.

Initial Speech Direction B to A

When a master station calls a substation it is often required that the conversation should have a fixed speech direction from the substation towards the master station.<br\> By using the AlphaCom Event Handler, it is possible to force the M-key on the B-subscriber ON when the conversation starts, and release the M-key when the conversation cancels. This will force the initial speech direction to be from the substation towards the master station. By operating the M-key, the master can override the speech direction. (In AlphaCom, the last one who is pressing the M-key will get the speech direction). If the master makes a short M-key press the conversation will turn to voice switched duplex.

Programming

From AlphaPro main menu, press the Users & Stations button. Select the master station from the list box, and press the Events button. Create a new event by pressing the “+” button. Select:

• Event type: 08 - Conversation Outgoing
• When Change to: ON
• When Related To: All
• Action: PAUSE

$M L%2.DIR

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Create a second event for the same master station by pressing the “+” button again. Select:

• Event type: 08 - Conversation Outgoing
• When Change to: OFF
• When Related To: All
• Action: $MREL L%2.DIR

<br\><br\> If there are several stations to have initial speech direction set, one can use a UDP group as Event Owner.

A UDP group is set as Owner of an event by selecting Exchange & System -> Events - > “+”. Now change the “Owner Type” to Station w. UDP. The ID field specifies which UDP group.

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Whole Exchange in Simplex Mode

If the Event Owner is set to UDP group 8, all stations will have initial speech direction from B to A.

Normally you can return to duplex mode by pressing the M-key quickly. In AMC there is a timer defining how short this M-key pulse have to be. If the timer is set to 0, it will not be possible to revert back from simplex to duplex. In this way all conversations will be in simplex mode. The timer is not available from AlphaPro, it has to be changed by using the nvram editor of the TST console.

TST>>nvram -  ex_profile.timeouts.short_m_pres 

Set this value to 0 (default value is 7). This will disable simplex to duplex by M-pulse.