Omron HOME SECURITY SYSTEM - MOTION SENSOR FQM1-MMA21 - Manual (Page 177)

154
Pulse Inputs Section 7-5
Counter Operation
(Numeric Ranges) The following two counter operations are available for high-speed counters 1
and 2, with the specified counting ranges.
Circular Counter
With a Circular Counter, the circular maximum count can be set in the System
Setup, and when the count is incremented beyond this maximum value, it
returns to zero. The count never becomes negative. Similarly, if the count is
decremented from 0, it returns to the maximum value.
The number of points on the circular is determined by setting the maximum
value (i.e., the circular maximum value), which can be set between 1 and
FFFF FFFF hex.
Linear Counter
With a Linear Counter, the count range is always 8000 0000 to 7FFF FFFF
hex. If the count decrements below 8000 0000 hex, an underflow is gener-
ated, and if it increments above 7FFF FFFF hex, an overflow is generated.
If an overflow occurs, the PV of the count will remain at 7FFF FFFF hex, and if
an underflow occurs, it will remain at 8000 0000 hex. In either case, counting
will stop and the PV Overflow/Underflow Flag shown below will turn ON to
indicate the underflow or overflow.
• High-speed counter 1: A608.01
• High-speed counter 2: A609.01
Note The high-speed counter PVs are refreshed during the Motion Control Mod-
ule’s I/O refresh.
When restarting the counting operation, toggle (turn OFF and then ON) the
corresponding counter’s Reset Bit. (A610.01 is the Reset Bit for high-speed
counter 1 and A611.01 is the Reset Bit for high-speed counter 2.)
Reset Methods The following two methods can be set to determine the timing at which the PV
of the counter is reset (i.e., set to 0):
• Phase-Z signal and software reset
• Software reset
Increment/Decrement Pulse Inputs Pulse + Direction Inputs
1
Increment Decrement
2
Encoder
Input A
(UP input)
Encoder
Input B
(DOWN input)
2 3 1 1
Increment Decrement
2
Encoder
Input A
(Pulse input)
Encoder
Input B
(Direction input)
2 3 1
Decrement Increment
Circular maximum value
0
Circular Counter Linear Counter
0
80000000 hex 7FFFFFFF hex
Underflow Overflow