162
Timers and Counters
Section 4-13
4-13 Timers and Counters
4-13-1 Timer Area (T)
The 4,096 timer numbers (T0000 to T4095) are shared by the TIM,
TIMX(550), TIMH(015), TIMHX(551), TMHH(540), TIMHHX(552), TTIM(087),
TTIMX(555), TIMW(813), TIMWX(816), TMHW(815), and TIMHWX(817)
instructions. Timer Completion Flags and present values (PVs) for these
instructions are accessed with the timer numbers.
The TIML(542), TIMLX(553), MTIM(543), and MTIMX(554) instructions do not
use timer numbers.
When a timer number is used in an operand that requires bit data, the timer
number accesses the Completion Flag of the timer. When a timer number is
used in an operand that requires word data, the timer number accesses the
PV of the timer. Timer Completion Flags can be used as often as necessary
as normally open and normally closed conditions and the values of timer PVs
can be read as normal word data.
The refresh method for timer PVs can be set from the CX-Programmer to
either BCD or binary.
Note It is not recommended to use the same timer number in two timer instructions
because the timers will not operate correctly if they are timing simultaneously.
(If two or more timer instructions use the same timer number, an error will be
generated during the program check, but the timers will operate as long as the
instructions are not executed in the same cycle.)
The following table shows when timers will be reset or maintained.
Note
1.
If the IOM Hold Bit (A500.12) is ON, the PV and Completion Flag will be
retained when a fatal error occurs (including execution of FALS instruc-
tions) or the operating mode is changed from PROGRAM mode to RUN or
MONITOR mode or vice-versa. The PV and Completion Flag will be
cleared when power is cycled.
2.
If the IOM Hold Bit (A50012) is ON and the PLC Setup’s IOM Hold Bit Sta-
tus at Startup setting is set to protect the IOM Hold Bit, the PV and Com-
pletion Flag will be retained when the PLC’s power is cycled.
3.
Since the TIML(542), TIMLX(553), MTIM(543), and MTIMX(554) instruc-
tions do not use timer numbers, they are reset under different conditions.
Refer to the descriptions of these instructions for details.
Instruction name
Effect on PV and Completion Flag
Operation in
Jumps and Interlocks
Mode change
1
PLC start-up
2
CNR(545)/CN
RX(547)
Jumps
(JMP-JME) or
Tasks on
standby
4
Interlocks
(IL-ILC)
TIMER: TIM/TIMX(550)
PV
→
0
Flag
→
OFF
PV
→
0
Flag
→
OFF
PV
→
9999
Flag
→
OFF
PVs refreshed in
operating timers
PV
→
SV
(Reset to SV.)
Flag
→
OFF
HIGH-SPEED TIMER:
TIMH(015)/TIMHX(551)
ONE-MS TIMER:
TMHH(540)/TMHHX(552)
ACCUMULATIVE TIMER:
TTIM(087)/TTIMX(555)
PV Maintained
PV Maintained
TIMER WAIT:
TIMW(813)TIMWX(816)
PVs refreshed in
operating timers
---
HIGH-SPEED TIMER WAIT:
TMHW(815)/TMHWX(817)
---
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...