GAI-Tronics MRTI 2000 (No. PL1877A) Microprocessor Radio Telephone Interconnect Installation & Service Manual - Manual (Page 78)

Operator Instructions PL1877A Microprocessor Radio Telephone Interconnect
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Linking Multi-Digit Release to Multi-Digit Access
When it is desired that all mobile users employ the same release code, the general multi-digit release
suffix is sufficient. However, for added security, it may be desirable to prevent the PL1877A from
disconnecting unless it receives a disconnect sequence from the same mobile user who originally entered
the multi-digit access sequence.
For example, suppose multi-digit access prefix #2 were 786. Also, suppose the general multi-digit
release suffix is 999. Thus, when a mobile entered 786*, the PL1877A would access the phone line. To
disconnect the phone line, the mobile user would enter #999. However, since 999 is a general multi-digit
release suffix that is known to all users of the system, any other mobile user could disconnect the call in
progress.
In addition to the general release suffix, the PL1877A provides four other release suffixes, each of which
corresponds to one of the multi-digit access prefixes.
• Multi-digit release suffix #1 (parameters 386 - 391) corresponds to multi-digit access prefix #1
(parameters 362–367).
• Multi-digit release suffix #2 (parameters 392 - 397) corresponds to multi-digit access prefix #2
(parameters 368–373).
• Multi-digit release suffix #3 (parameters 398 - 403) corresponds to multi-digit access prefix #3
(parameters 374–379).
• Multi-digit release suffix #4 (parameters 404 - 409) corresponds to multi-digit access prefix #4
(parameters 380–385).
The PL1877A can be programmed to require the corresponding multi-digit release suffix when the
mobile user has accessed the phone line via a multi-digit access prefix. For example, suppose multi-digit
release suffix #2 is 546. Then, when the mobile user accessed the PL1877A by entering 786*, the
sequence #546 would be required to cause disconnection.
N OTE : If the associated multi-digit release suffix is not enabled, the PL1877A requires the general
multi-digit release suffix. If the general multi-digit release suffix is not enabled, the PL1877A simply
disconnects in response to the # (##) disconnect command.
Installation
To force the user of a multi-digit access prefix to use the associated multi-digit release suffix, set
parameter 39 = 1. Then enter the release suffix digits in the appropriate parameters, as listed above. The
PL1877A can be programmed to use multi-digit release prefixes instead of suffixes. If this is desired, set
parameter 40 = 1. In this case, the general multi-digit release code (and all multi-digit release codes
corresponding to the multi-digit access prefixes) is a prefix to the # (or ##) release command. The
wildcard access/release feature provides a mobile user with the ability to create a unique access prefix
each time a call is placed or answered. This access prefix then becomes the release suffix (or prefix,
depending on parameter 40), which is required to disconnect the call.
For example, suppose a mobile user accessed the PL1877A with the code 1776*. Then, to release the
PL1877A, that user would be required to enter #1776 (or 1776#, depending on whether the PL1877A is
programmed for multi-digit release prefixes or suffixes by parameter 40).
On the next call, the mobile user might access the PL1877A with the code 1812*. Then, to release the
PL1877A, the required code would be #1812 (or 1812#). Notice that the mobile user used two entirely
different access prefixes in each case above. In fact, the mobile user could enter a different prefix each
time the PL1877A is accessed. In each case, the PL1877A would require a release suffix (or release
prefix, depending on parameter 40) that exactly matched the access prefix.