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High-speed Counters
Section 5-2
Lower and Upper Limits of the Range
The following diagrams show the lower limit and upper limit values for incre-
ment mode and up/down mode.
Circular (Ring) Mode
Input pulses are counted in a loop within the set range. The loop operates as
follows:
• If the count is incremented from the max. ring count, the count will be
reset to 0 automatically and incrementing will continue.
• If the count is decremented from 0, the count will be set to the max. ring
count automatically and decrementing will continue.
Consequently, underflows and overflows cannot occur when ring mode is
used.
Max. Ring Count
Use the PLC Setup to set the max. ring count (Circular Max. Count), which is
the max. value of the input pulse counting range. The max. ring count can be
set to any value between 00000001 and FFFFFFFF hex.
Restrictions
• There are no negative values in ring mode.
• If the max. ring count is set to 0 in the PLC Setup, the counter will operate
with a max. ring count of FFFFFFFF hex.
Reset Methods
Phase-Z Software
Reset
The high-speed counter's PV is reset when the phase-Z signal (reset input)
goes from OFF to ON while the corresponding High-speed Counter Reset Bit
is ON.
The CPU Unit recognizes the ON status of the High-speed Counter Reset Bit
only at the beginning of the PLC cycle during the overseeing processes. Con-
4294967295
(FFFFFFFF hex)
−
2147483648
(80000000 hex)
0
(00000000 hex)
+2147483647
(7FFFFFFF hex)
PV overflow
Increment Mode
Up/Down Mode
PV underflow
PV overflow
0
(000000 hex)
2
32
−
1
0
Count value
Max. ring
count
Summary of Contents for CP1H-CPU - 05-2006
Page 2: ...CP1H X40D CP1H XA40D CP1H Y20DT D CP1H CPU Unit Operation Manual Revised May 2006...
Page 3: ...iv...
Page 11: ...xii TABLE OF CONTENTS...
Page 15: ...xvi...
Page 19: ...xx...
Page 31: ...xxxii Conformance to EC Directives 6...
Page 71: ...40 Function Blocks Section 1 5...
Page 133: ...102 Computing the Cycle Time Section 2 7...
Page 169: ...138 CPM1A Expansion I O Unit Wiring Section 3 6...
Page 411: ...380 Clock Section 6 8...
Page 519: ...488 Replacing User serviceable Parts Section 10 2...
Page 527: ...496 Standard Models Appendix A...
Page 535: ...504 Dimensions Diagrams Appendix B...
Page 628: ...597 Connections to Serial Communications Option Boards Appendix F Connecting to Unit...
Page 629: ...598 Connections to Serial Communications Option Boards Appendix F...
Page 659: ...628 PLC Setup Appendix G...
Page 665: ...634 Index work words 159 write protection 370...
Page 667: ...636 Revision History...