ZETRON Model 25, Руководство по эксплуатации продукта

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Encoder Installation
025-9567E 41
There are two options for the use of the control relays. The control relays may be used to
directly key the channels (direct keying mode) or they may be used to automatically select
the channels on the console (momentary select mode). The selection of the keying method is
done through programming.
Using the direct keying option, the control relays are used to directly key up to eight
transmitters. The control relays along with PTT will remain closed for the entire duration of
the calling sequence. Using this option, the PTT relay is typically wired in series with the
control relay common point so that each control relay acts like a PTT for the transmitter
wired to it.
The momentary select option uses a momentary closure (pulse) of the control relays to select
one or more channels automatically just prior to closing the PTT relay. The pulse action of
the control relays emulates the electrical signal generated by the momentary press of a
console “select” key. Using this option the PTT relay is typically wired across the console
PTT and the eight control relay contacts are wired either directly to the channel select key or
to some point in the channel’s Tx/Rx module. If the select keys on the console are a function-
toggle type (push to select, push again to de-select) or a latching type (switch down when
selected) then, the control relays must not be wired directly to the select keys.
Occasionally, it may be necessary to transmit over more than one channel at a time. If this is
required of a system attached to a console, then the encoder may also control the console
simul-select signal. The Audio relay, if not required for audio steering/muting purposes, may
be used for simul-select control via programming. When the simul-select control is enabled,
the Audio relay lags the opening and closing of the eight control relays by 100 milliseconds.
This allows the control relays to cancel the selection previously made on the console prior to
turning on simul-select. After transmission, the simul-selected channels will remain selected
to allow convenient transmission of the voice message.
Another programmable channel control parameter is the transmitter key-up delay. The key-
up delay that is programmed is used for all channels or transmitters that the Model 25
controls. The transmitter key-up delay is the duration between closure of PTT and the
beginning of encoding tones. This delay is programmable in 100 millisecond increments
from 0.1 to 9.9 seconds.
Table 12 shows the connections for the control and PTT relays for a typical direct keying
application. Since the wiring for momentary select applications is so varied, the details of the
connections are described for different types of consoles in the applications appendix in the
back of this manual. If your type of console is not shown, then Zetron Technical Support can
help you find suitable console connection points.