GAI-Tronics MRTI 2000 (No. PL1877A) Microprocessor Radio Telephone Interconnect Installation & Service Manual - Manual (Page 77)

PL1877A Microprocessor Radio Telephone Interconnect Operator Instructions
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To satisfy these differing requirements, you create two multi-digit access prefixes. To those mobiles that
must manually dial phone numbers starting with 0, you assign the prefix 1938; to those mobiles that are
only allowed to use the auto-dial feature, you assign the prefix 1941.
1938 is treated as multi-digit access prefix #1. Therefore, it is programmed into parameters 362–367
(362 = 1; 363 = 9; 364 = 3; 365 = 8; 366 = FF; 367 = FF). In order to bypass the restriction on manual
mobile dialing (restriction #4) and the restriction on dialing phone numbers beginning with 0 (restriction
#7), parameters 515-517 are programmed as follows:
515 = $10 (hexadecimal 10; bit 4 = 1)
516 = 8 (bit 3 = 1)
517 = 0
1941 is treated as multi-digit access prefix #2. Therefore, it is programmed into parameters 368–373
(368 = 1; 369 = 9; 370 = 4; 371 = 1; 372 = FF; 373 = FF). In order to bypass the restriction on
autodialing (restriction #6), parameters 518-520 are programmed as follows:
518 = 4 (bit 2 = 1)
519 = 0
520 = 0.
If the security code suffix was enabled and a mobile user was acquainted with it, the security code could
be transmitted to allow autodialing, manual dialing, AND bypassing the restriction on telephone numbers
starting with 0.
Configuring the Security Code to Bypass Restrictions
As indicated in the previous table, the multi-digit access prefixes have the potential to bypass 18
programmed restrictions. The security code bypasses all 18 of these restrictions. It may not be desirable
to allow all 18 of these restrictions to be bypassed by the security code. It is possible to configure the
security code to bypass only certain restrictions. However, doing so limits the number of restrictions that
can be bypassed by a single multi-digit access prefix.
For example, you may require that the security code cannot bypass the restriction on manual dialing.
This is possible, but to require this also results in none of the multi-digit access prefixes being capable of
bypassing the restriction on manual dialing.
N OTE : As a general rule, a multi-digit access prefix can only bypass restrictions that are definitely
bypassed by the security code. Parameters 527–529 are used to configure the security code to bypass
restrictions.
• The structure of parameter 527 exactly matches the structure of parameters 515, 518, 521, and 524.
• The structure of parameter 528 exactly matches the structure of parameters 516, 519, 522, and 525.
• The structure of parameter 529 exactly matches the structure of parameters 517, 520, 523, and 526.
Multi-Digit Release
The multi-digit release feature requires a DTMF suffix following the # (or ##) release command. If the
PL1877A does not receive this suffix, it will not respond to the release command. This feature is used
when it is desirable to allow the mobile user to dial a DTMF # without causing phone line disconnection.
N OTE : Consider the multi-digit release sequence #XYZ where XYZ is the 3-digit multi-digit release
suffix to the # release command. The PL1877A recognizes XYZ as a multi-digit release suffix only if the
time between individual digits (represented by the “–” in #–X–Y–Z) is no greater than 1 second. Also,
the duration of each digit must be no greater than 3.5 seconds. The multi-digit release suffix (hereafter
referred to as the general multi-digit release suffix) is defined by parameters 410–415. It can consist of
DTMF digits from 0-D. Fill all unused digits with FF (hexidecimal FF). If all digits are filled with FF,
the general multi-digit release suffix is disabled.