E F Johnson Company 2425341 Benutzerhandbuch

55

and 1-16 when the SLN mode is selected (see 
Figure 11-1).

PID or SLN key management modes can be 

programmed on the Global programming screen. More 
information on these modes follows.

PID Mode - The PID mode can be used only when 
keys are loaded using the Motorola KVL 3000 
keyloader. When this mode is selected, keys are loaded 
directly into a PID of 0-15 that corresponds to the PID 
programmed for each channel (if applicable). A Keys 
Table is not programmed with this mode.

SLN Mode - The SLN mode must be selected is either 
OTAR (Over-The-Air-Rekeying) or the EFJohnson 
System Management Assistant (PDA keyloader) is 
used. It can also be used if OTAR is not used. With 
this mode, keys are loaded into a SLN (Storage Loca-
tion Number), typically from 0-4095. A Keys Table 
must then be programmed to link channel PIDs to a 
specific SLN. 

The use of this type of indirect linking allows keysets 
and key IDs to be changed via OTAR while keeping 
the mapping from the channel or talk group the same. 
For example, as shown in Figure 11-1, PID 4 selects 
SLN 24 which selects key slot 24 in both keysets. This 
slot contains Key ID 69 in Keyset 1 and Key ID 91 in 
Keyset 2. Only one keyset is active at a time. 

11.2.4  MAINTAINING KEYS IN MEMORY

The radio may need to be connected to a constant 

power source to preserve the encryption keys in 
memory. The programming of the Infinite Key Reten-
tion parameter determines if keys are permanently 
stored in memory or erased soon after power is 
removed. This parameter is available in 5100 models 
with firmware 1.11.0/2.0/3.0 or later. 

When Infinite Key Retention is enabled, keys are 

stored in memory and are not lost when power is 
removed. If it is disabled, they are maintained only 
until the storage capacitance discharges. With 5100 
portable models, storage capacitors maintain the 
supply voltage (and encryption keys) for approxi-
mately 30 seconds without power applied. Therefore, 
when changing the battery, make sure to reattach 
another within 30 seconds.

With 5300 mobile models, the keys are main-

tained for approximately 8 hours with this feature 
disabled. However, a tamper switch causes immediate 
key erasure when the radio cover over the logic board 
is removed.

11.2.5  ENCRYPTION KEY SELECT

When multiple encryption keys are programmed 

(see preceding information), the KY SEL option 
switch can be programmed to allow selection of 
another key for the current channel. This feature 
changes the PID (hardware location) of the key, and 
the change is permanent (cycling power or selecting a 
different channel does not reselect the original key). 
Therefore, to switch back to the original key, it must 
be manually reselected. Proceed as follows to select a 
key:

1. Press the KY SEL option switch and HWKEY x is 

displayed. The “x” indicates the current key PID 
selection. 

2. Rotate the Select switch to display the desired key 

and then press the Select switch to select it. Press the 
KY SEL option switch again to return the display to 
normal operation.

11.2.6  ENCRYPTION KEY ERASE

A KY CLR option switch can be programmed 

that allows the user to permanently erase all stored 
keys. If OTAR TEK and KEK keys are stored, all keys 
of both types are erased. This function can be used to 
ensure that unauthorized encrypted calls can no longer 
be placed or received by a radio.

11.3.1  TRANSMIT MODE OPTIONS

The following transmit options are available 

when encryption is selected:

Clear - All calls are in the clear mode unless 
responding to a secure call. If the response is then 
made within the delay time (see Section 4.11.4), it 
occurs in the secure mode.