VXI VT1433B - Manual (Page 133)

Input Count Division
The tachometer can be programmed to divide the input signal. For example if a
signal is coming in at 100 counts per second, the tachometer can be set to look at
only every 10th count for a result of 10 counts per second.
Holdoff Time
The tachometer can be programmed to wait for a specified period of time between
counts that it will detect. After a count is detected, subsequent counts will be
ignored until the holdoff time has passed.
Block Diagram
VT1433B User's Guide
The Tachometer Option
7-3
Channel 2
Tach/Ext Trig
Channel 2
Tach
Analog
Conditioning
Analog
Conditioning
Holdoff Ctrl
1 of N select
Holdoff Ctrl
1 of N select
System
Trigger
32-bit
Latch
32-bit
Latch
32-bit
Counter
FIFO
FIFO
DSP “B” Bus
or paged A24 VXI
Ctrl & Status
Registers
10 - 20 MHz
Reset
Figure 7-1: Tachometer option block diagram