GAI-Tronics MRTI 2000 (No. PL1877A) Microprocessor Radio Telephone Interconnect Installation & Service Manual - Manual (Page 72)

Operator Instructions PL1877A Microprocessor Radio Telephone Interconnect
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Landline Originated Calls
The landline (telephone-originated) call proceeds in two different manners, depending upon installed
options. If special information (access code, selective signaling code, etc.) is required to initiate mobile
signaling, refer to the applicable section in this manual for operational details.
When the landline caller dials the phone patch, the unit detects ringing on its line (as indicated by the
flashing
CONN LED). After ensuring that the channel is available (not receiving carrier and not sensing
PTT), the patch transmits one 3-second ring tone. To answer the call, the mobile operator presses * on
the encoder after the ring tone ceases. The patch accesses the telephone line and conversation may
proceed as outlined previously. When the conversation is over, the mobile or telephone user sends a # to
release the telephone line. The patch confirms release with a series of short beep tones.
Direct Access
N OTE : Direct Access is used for portables with no DTMF keypad.
The landline caller dials the phone patch. The unit detects ringing on its line and accesses the phone line.
Then, the patch generates two beeps. After ensuring that the channel is clear, the patch transmits one
3-second ring signal to the mobile. Immediately following this ring, the audio paths between phone and
radio are established. The telephone user may speak over the air according to the instructions regarding
conversations outlined previously. When the allowed time for direct channel access expires, the patch
automatically releases the phone line.
Selective Signaling
The landline caller dials the phone patch. The unit detects ringing on its line and accesses the phone line.
Then, the patch generates two beeps, to indicate it is awaiting input (the desired capcode digits or user
ID) from the phone user. When the proper number of digits is received, three beeps are generated.
After ensuring that the channel is clear, the signaling sequence is transmitted. If the patch is programmed
for direct access, the audio paths between phone and mobile are established immediately following the
signaling transmission. The path automatically releases the phone line when the direct access time
expires. If the patch is not programmed for direct access, it waits for a mobile to respond by sending the
access command. If a mobile does not respond in the time set by parameters, the patch disconnects.
N OTE : When the patch attempts to transmit the direct access ring or the selective signaling sequence, it
checks for a clear channel (absence of mobile carrier and station PTT). If the channel is not clear, the
phone user hears busy tones until the channel clears or until one minute has transpired. If the channel
remains busy for one minute, the patch aborts the call.