E F Johnson Company 2425M70 Benutzerhandbuch

8-4

or digital encryption, and can also be used with the with the Motorola KVL-3000 Plus. 
With this mode, keys are loaded into a SLN (Storage Location Number), typically from 
0-4095. The 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 
through OTAR while keeping the mapping from the channel or talkgroup the same. For 
example, as shown in Figure 8.1, 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. The actual key chosen between these two to transmit with will 
depend on which keyset is active, Keyset 1 or Keyset2.

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 Retention parameter determines if 
keys are permanently stored in memory or erased soon after power is removed.

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 removed almost immediately after power is 
turned off.

With Viking VM600 mobile models, the keys are maintained for approximately eight 
hours with this feature disabled. However, a tamper switch causes immediate key erasure 
when the radio cover over the logic board is removed.

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 of the channel for 
analog or Talkgroup for Conventional Digital and P25 Trunking, 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.