7
OPERATION
Mode Selection:
The mode of the VPU-12A can be controlled by a momentary or latched switch.
Latched Switch:
Programming the VPU-12A to latched with a Mode Polarity of +/- will cause the scrambler to
be in clear mode when high and scramble mode when taken to ground. A Mode Polarity of -/+ will cause the
scrambler to be in clear mode when taken to ground and scramble mode when high.
Momentary Switch:
Programming the VPU-12A to momentary with a Mode Polarity of +/- will cause the
scrambler to toggle modes when taken to ground. A Mode Polarity of -/+ will cause the scrambler to toggle
modes when taken high.
Code Selection:
Single Code:
If only a single inversion frequency is desired connect the frequency select lines to ground as
indicated in Table 1 above. Otherwise if no frequency select lines are grounded code 16 will be selected.
Multi-Code:
The VPU-12A has a 4-line binary input that can be used to select from 16 different inversion
frequencies (see Table 1 above).
