Vega DSP-223, Technical Manual

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8 Vega DSP-223
4.2.2 DSP-223 Configuration
Each button and programming field is described in the sections that follow.
4.2.2.1 Function Tone Mode
In the upper left corner is a selection for single or dual function tone mode. Single function tone mode
requires that the controlling console generate its Guard tone and then a single 40ms function tone. Dual
function tone mode requires that the controlling console generate the Guard tone and then two
consecutive function tones, which are then combined to form a 00-99 function tone. The standard
function tones and their frequencies are shown in the following table.
Function Tone
Number
Frequency
(Hz)
Function Tone
Number
Frequency
(Hz)
F1 1950 F9 1150
F2 1850 F10 1050
F3 1750 F11 950
F4 1650 F12 850
F5 1550 F13 750
F6 1450 F14 650
F7 1350 F15 550
F8 1250 F16 450
Dual function tones use tones F1-F10 and construct the final function tone value by combining the first
received tone as the tens digit and the second received tone as the ones digit. F10 is used as a zero.
For example: Function tone 9 would be transmitted as F10-F9, Function tone 43 would be F4-F3, and so
forth.
It is very important that DSP-223 be programmed for the type of signaling that is being sent from the
controlling consoles. It is possible to put the unit into the dual tone mode and send single tones and have
it recognize them correctly. This mode is more prone to errors however. The best way to make this work
is to make certain that no tones are sent for 40ms after the first function tone is sent so that a no tone can
be decoded. If the 2175 hold tone, or other audio is present, the DSP-223 will attempt to decode this as
the second half of the dual function tone.
The DSP-223 will also error beep back to the console if it was unable to decode a function sequence from
the console. This consists of a short sequence of 3-4 beeps.
Selecting single or dual function tone mode will set the number of function tones that can be programmed
by scrolling in the data entry table between 16 and 100 respectively.
4.2.2.2 CTCSS Tone
Two options are provided to set the CTCSS operation. PTT Only sets the CTCSS generator active during
PTT detection only. Always On sets the CTCSS tone generator active at all times regardless of the PTT
status.
4.2.2.3 PTT Options
The PTT Options Section configures the DSP-223 while PTT is active. These options control the PTT
relay, R1 and R2 relays with respect to PTT, the received console PTT frequency as well as the PTT
mode.
PTT Frequency selects the Hold tone frequency received from the console. The selectable frequencies
are:
2100 Hz 2325 Hz
2155 Hz 2600 Hz
2175 Hz 2800 Hz
2300 Hz 2970 Hz