Rockwell Automation 1771-VHSC , D17716.5.74 Very High S - Manual (Page 67)

Appendix
D
Questions and Answers
This appendix presents some of the more commonly asked questions
about application and operation of the Very High Speed Counter
module.
The following questions and answers do not cover all possible
questions, but are representative of the more common ones.
Q. If I do not connect channel B in counter mode, what
happens to the count status?
A. With channel B disconnected or tied low, the module will count
up only. If channel B is tied high, it will count down.
Q. What happens when my processor faults?
A. All outputs will turn off, regardless of the last state switch in
the I/O rack.
Q. What happens to my outputs if I place the processor in
program mode?
A. All outputs turn off. The inputs will remain active and the
module will keep track of count changes. When the processor
is returned to RUN mode, the outputs will not become active
until after the first valid BTW, and then will be based on the
current count.
Q. What does it mean when the indicator for a particular
input is on.
A. If the indicator is on, it means that the input is tied high. If the
indicator is off, the input is floating or tied low.
Q. What do my indicators mean if I configure the gate input to
be inverted?
A. The gate indicator will illuminate when the input is tied high,
and turns off when floating or tied low. The gate inversion is
seen internally by the module.
General
Questions and Answers