GAI-Tronics MRTI 2000 (No. PL1877A) Microprocessor Radio Telephone Interconnect Installation & Service Manual - Manual (Page 124)

Features PL1877A Microprocessor Radio Telephone Interconnect
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The *2* command can also be used when the PL1877A is generating a busy signal to the mobile. When
the PL1877A attempts to access the phone line for a mobile originated call, it returns a busy signal if it
detects that the line is in use by a line-sharing telephone set. If the mobile wishes to bypass the busy line
and place the call on line 2, he can dial *2*. The PL1877A switches to line 2 and attempts the call on
that line.
N
OTE : If the mobile user switches to line 2 in response to busy signaling (as described above), it is not
necessary to re-enter the access command. When the PL1877A switches to line 2, it automatically
accesses the phone line. If the mobile had previously entered an auto-dial or redial command, the
PL1877A proceeds with auto-dialing or redialing the telephone number.
The *2# command can be used to immediately return the PL1877A to line 1 when line 2 has already been
selected. For example, if the PL1877A detects ringing on line 2, switches to line 2, and rings the mobile,
the mobile user can command the PL1877A back to line 1 (in order to originate a call) via the *2#
command. *2# can also be used when the PL1877A returns busy signaling (as described previously) to
the mobile because line 2 is in use by a line-sharing telephone set.
Selective Signaling
The PL1877A supports single-mode and multi-mode selective signaling. In single-mode selective
signaling, the PL1877A is programmed to use only one paging type (DTMF, 2 tone, etc.) for all mobiles.
In multi-mode selective signaling, the PL1877A is capable of paging 100 mobiles, each of which has its
own defined paging type. In multi-mode operation, each mobile is assigned a user ID from 0 to 99.
The selective signaling feature may be operated by:
1. A land line caller with a DTMF or rotary telephone;
2. An attendant (the user of a DTMF telephone that shares the same phone line as the PL1877A);
3. A mobile user with a DTMF encoder.
Parameter settings determine which of these are allowed (any, all, or none).
Landline Caller
The caller dials the telephone number of the PL1877A. When the PL1877A answers, it normally
generates two beeps to indicate that it is waiting on the landline user to enter the required capcode digits
or user ID.
N OTE : If the PL1877A is programmed to require a landline access code before allowing selective
signaling (parameter 50 = 1 or parameter 43 = 1), then it answers the phone line with one beep. After the
landline user has entered * (possibly preceded by an access prefix - parameters 133-138), the PL1877A
generates two beeps and awaits the paging input digits.
The caller is allowed a certain time (set by parameter 1089) to enter the first input digit. When the
proper number of digits has been entered, the PL1877A generates three beeps. Then, the PL1877A
checks for a clear channel before paging the mobile. If the channel is busy, the PL1877A returns busy
tones to the landline. The PL1877A continues to check for a clear channel for a maximum of one
minute. If the channel is not clear at the end of 1 minute, the PL1877A disconnects.
When the channel is clear, the PL1877A pages the mobile. Then, if the PL1877A is not programmed for
direct access, it waits for the mobile to answer. Otherwise, the PL1877A immediately patches the
landline user through to the channel for the duration of the direct access timer.
If the landline user takes too long to enter the paging input digits, the PL1877A responds in one of 3
ways, depending on the value of parameter 1082. It either disconnects the land-line, transmits ring
signaling to the mobiles, or pages user ID 00 (if user ID 00 has been enabled).