GAI-Tronics MRTI 2000 (No. PL1877A) Microprocessor Radio Telephone Interconnect Installation & Service Manual - Manual (Page 79)

PL1877A Microprocessor Radio Telephone Interconnect Operator Instructions
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The wildcard access/release feature is generally used to increase the level of security beyond that
provided by the standard multi-digit access/release feature. Since the standard multi-digit access and
release codes are fixed, security is limited by the number of mobile users who know the codes.
For example, if the PL1877A is programmed to require a multi-digit release suffix from the mobile user,
anyone who knows the required suffix can cause disconnection of the conversation. However, with
wildcard access/release, it is unlikely that anyone would be able to disconnect a call in progress except
the mobile user who originated it via a wildcard access prefix.
Wildcard Access/Release Installation
The wildcard feature can be programmed to require wildcard access prefixes from 1 to 6 digits in length.
Note that the feature does not support variable length prefixes – that is, if the feature is programmed for
3-digit wildcard access prefixes, then ALL wildcard access prefixes (and the corresponding wildcard
release suffixes/prefixes) must be 3 digits in length, etc.
Furthermore, some of the digits in wildcard codes can be set to specific values. For example, you can
program the PL1877A such that all wildcard prefixes are of the form x3x where x is a wildcard digit (that
is, a digit chosen by the mobile user when the prefix is used). In this case, the mobile user could access
the PL1877A only with 3-digit access prefixes in which the 2nd digit is 3.
The features described above are determined by programming parameters 530–535. This group of
parameters is referred to as the wildcard template since it defines the structure that all valid wildcard
prefixes must match. To program the wildcard template, follow the steps listed below:
1. Determine how many digits you want in all wildcard prefixes. The allowable range is 1–6.
2. Determine whether you want any fixed digits in all wildcard prefixes.
For example, suppose you have decided that you want all wildcard prefixes to be four digits in length
and conform to the structure 3xx2 (where x represents a wildcard digit).
3. Program the required values into the wildcard template.
For the example above, you have chosen 3xx2 as the required wildcard structure. The last digit of
your wildcard structure must be programmed into parameter 535. Thus, you would program
parameters 530–535 as follows:
parameter 530: FF
parameter 531: FF
parameter 532: 3
parameter 533: F
parameter 534: F
parameter 535: 2
Notice that all unused locations must be programmed with the value FF (hexadecimal FF). All
wildcard digits must be programmed with the value F (hexadecimal F).