GAI-Tronics MRTI 2000 (No. PL1877A) Microprocessor Radio Telephone Interconnect Installation & Service Manual - Manual (Page 126)

Features PL1877A Microprocessor Radio Telephone Interconnect
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If a landline user attempts to transmit a group call when parameter 1009 specifically forbids group
calling, the PL1877A disconnects. If an attendant user attempts to transmit a group call when parameter
1010 specifically forbids group calling, the PL1877A disconnects. If a mobile user attempts to transmit a
group call when parameter 1011 specifically forbids group calling, the PL1877A ignores the mobile
revertive paging command (*##n, where n is the paging input).
2-Tone Group Calls
A 2-Tone Group Call is an 8-second tone burst of a specified frequency. It alerts all devices whose 2-
tone capcodes consist of B tones matching the group call tone. For example, an 8-second burst of
330.5 Hz would alert all devices whose 2-tone capcodes consisted of B tones of frequency 330.5 Hz.
N OTE : GE systems do not support this method of group calling. Therefore, 8-second tone bursts are not
generated if the selected code plan is the GE code plan (parameter 1129 = $23). If identical A and B
tones are specified for a capcode under the GE codeplan, the A tone is replaced by the diagonal tone of
742.5 Hz.
Dual Addressing
Dual Addressing applies to Motorola/EIA 5-Tone paging. The 5-tone paging sequences transmitted by
the PL1877A consist of 5 tones. However, if enabled by parameter 1012, the PL1877A can generate 5-
tone paging sequences that consist of a 6th tone (the dual address tone). This sixth tone is always the
same frequency (2010 Hz).
When dual addressing is enabled through parameter 1012, the PL1877A requires that all 5-tone capcodes
consist of six digits. The sixth digit is either 0 or 1. If the dual address tone is to be generated, the sixth
digit must be 1; otherwise, the sixth digit must be 0.
Single-Mode Selective Signaling
When the PL1877A is programmed for single-mode selective signaling, input is normally required from
the user (landline, attendant, or mobile user). This input specifies all or some of the target device’s
capcode digits.
The number of input digits required from the landline user is determined by parameter 1083. The
number of input digits required from the attendant user is determined by parameter 1084. The number of
input digits required from the mobile user is determined by parameter 1085.
Suppose, for example, that the PL1877A is programmed for 5-tone, single-mode selective signaling
(parameter 1081 = 5). Suppose also that your system is configured such that the capcodes of all 5-tone
devices are of the form 88xyz. You wish to allow the landline user to page only a limited group of
mobiles - capcodes 88120 through 88129. You wish to allow mobile and attendant users to page any
mobile in the system - capcodes 88000 through 88999.
To accomplish this, program parameter 1083 to 1. This sets the PL1877A to require one input digit from
landline users. Program parameters 1084 and 1085 to 3. This sets the PL1877A to require three input
digits from attendant and mobile users.
Then, 8812 must be programmed into the preprogrammed 5-tone capcode (parameters 1165-1170).
(Parameters 1169 and 1170 would be programmed with $FF since they are unused). The PL1877A
draws whatever digits it needs from this capcode. Thus, since landline users enter only one digit, the
PL1877A draws the first four capcode digits (8812) from these parameters. Since attendant and mobile
users enter three digits, the PL1877A draws the first two capcode digits (88) from these parameters.