Contec CNT24-4D(PCI), Руководство пользователя

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I/O Port Bit Assignment
CNT24-4D(PCI)
36
Each Counter Operating Mode
2-phase Input
Two-phase input is to input two pulses of phase A (the leading
signal) and phase B (the trailing signal) which differ by 90?.
When phase Z (the reference position signal) is available, the
counter can be cleared with 2-phase pulse input.
Phase A
(Phase A/UP)
Phase B
(Phase B/DOWN)
Phase Z
(Phase Z/CLR)
Count value
0 1 2
* The above represents counting operations when DIR is set to 1. When DIR
is set to 0, counting down takes place at the leading edge of phase A.
Figure 5.4. Example counting during 2-phase input
Single-phase Input
During single-phase input, input of an UP pulse results in counting
up while input of a DOWN pulse results in counting down. If UP
and DOWN pulses are simultaneously generated or both pulses
change to LOW, normal counting does not take place.
UP pulse
(Phase A/UP)
DOWN pulse
(Phase B/DOWN)
Count value
6
7
8
* The above represents counting operations when DIR is set to 1. When DIR is set to 0, counting
down takes place at the leading edge of the UP pulse and counting up takes place at the leading
edge of the DOWN pulse.
5
7
6
Figure 5.5. Example counting during single-phase input