B-40 | ni.com
Appendix B Timing Diagrams
Quadrature and Two Pulse Encoder Timing
Counter n A, Counter n B, and Counter n Z, described in the
Counter n A, Counter n B, and
Counter n Z Signals
section of Chapter 7, Counters, are used in position measurements using
quadrature encoder or two-pulse encoder counting modes. Table B-35 shows the timing
requirements for these signals.
Figure B-51. Quadrature and Two Pulse Encoder Timing Diagrams
Table B-35. Quadrature and Two Pulse Encoder Timing
Time Description Min (ns)
*
Max (ns)
t
14
Counter n A Period 50.0 —
t
15
Counter n A Pulse Width 25.0 —
t
16
Counter n B Period 50.0 —
t
17
Counter n B Pulse Width 25.0 —
t
18
Counter n Z Pulse Width 25.0 —
t
19
Delay from Counter n A to Counter n B 25.0 —
t
20
Delay from Counter n B to Counter n A 25.0 —
*
The times in this table are measured at the pin of the M Series device. For example, t
14
specifies the
minimum period of a signal driving a PFI, RTSI, or PXI_STAR pin when that signal is internally routed
to Counter n A.
Counter n A
t
15
Counter n Z
t
15
t
14
Counter n B
t
17
t
17
t
16
t
19
t
18
t
20
t
18