GAI-Tronics IPE2500A, IPE2500A-MLS Paging Encoder / Desktop Controller User and Installatoin Manual - Manual (Page 32)

Operation IPE2500A and IPE2500A-MLS Paging Encoder/Desktop Controller
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2-Tone Paging Example
Example 1
Suppose the number of 2-Tone keypad digits accepted from the user on the selected channel is 2, and
Code Plan R has been selected. The 8-second group call has been selected and the preset 2-Tone digit is
7. Also, the A tone length is set to 1 second and the B tone length is set to 3 seconds.
If the console operator entered the digits 43 and pressed the
TRANSMIT
button, the console would
generate 1251.4 Hz for 1 second followed by 669.9 Hz for 3 seconds. These tone frequencies are located
on Tone Group Frequency Chart according to the following procedure.
1. Locate the chosen code plan (R in this example) on the Code Plans Table on page 27.
2. From the same chart, locate the most significant digit (MSD) of the 2-Tone prefix (7 in this
example).
3. Next, determine the two-digit number that appears at the intersection of the code plan row and the
MSD column (62 in this example).
4. The first digit of this number (6 in this example) corresponds to a number under the Group # heading
on the Tone Group Frequency Chart on page 28, and indicates which row of frequencies on the chart
will be used for the A tone. In this example, the A tone number entered by the console operator is 4,
which corresponds to 1251.4 Hz.
5. The second digit of the number from chart B (2 in this example) also corresponds to a number under
Tone Group Frequency Chart Group #, and indicates which row of frequencies on chart will be used
for the B tone. In this example, the B tone number entered by the console operator is 3, which
corresponds to 669.9 Hz.
The previous example involves the console operator being required to enter two digits from the keypad
(programming the number of 2-Tone digits accepted from the user on the selected channel to 2).
However, if all three digits were required from the console operator (programming the number of 2-Tone
digits accepted from the user on the selected channel to 3), the procedure for finding the frequencies from
the Tone Group Frequency Chart would be the same, except that the most significant digit of the prefix
would be the first digit entered from the keypad.
If no digits were required from the operator (programming the number of 2-Tone digits accepted from the
user on the selected channel to 0) both the A and B tone frequencies would be predetermined through
programming and the same tone sequence would be sent every time a 2-Tone page is generated on this
particular channel.
Group Call
A group call occurs when both tones of a 2-Tone paging sequence are the same frequency. If the console
is programmed to allow 8-second group calls on a particular channel, then whenever a paging sequence is
generated that consists of two tones of the same frequency, the page consists of an 8-second burst of that
tone frequency.
However, 8-second group calls do not apply when the GE code plan has been selected. In the GE system,
a “diagonal” tone of 742.5 Hz is inserted in place of the first tone if that tone is the same as the second
tone.