Omron CPM1 Programming Manual page 168

SRM1 Memory Area Functions
3-3-3 SR Area
3-3-4 TR Area
3-3-5 HR Area
3-3-6 AR Area
3-3-7 LR Area
3-3-8 Timer/Counter Area
These bits mainly serve as flags related to SRM1 operation or contain present
and set values for various functions. For details on the various bit functions,
refer to relevant sections in this manual or to Appendix C Memory Areas.
SR 240 to SR 247 and SR250, 251 can also be used as work bits, when input
interrupts are not used in Counter Mode. SR232 to SR239 can also be used
as work bits when the MCRO (99) instruction is not being used.
When a complex ladder diagram cannot be programmed in mnemonic code
just as it is, these bits are used to temporarily store ON/OFF execution condi-
tions at program branches. They are used only for mnemonic code. When
programming directly with ladder diagrams using the Ladder Support Soft-
ware (LSS) or the SYSMAC Support Software (SSS), TR bits are automati-
cally processed for you.
The same TR bits cannot be used more than once within the same instruction
block, but can be used again in different instruction blocks. The ON/OFF sta-
tus of TR bits cannot be monitored from a Peripheral Device.
Examples showing the use of TR bits in programming are provided on
page 173.
These bits retain their ON/OFF status even after the SRM1 power supply has
been turned off or when operation begins or stops. They are used in the same
way as work bits.
These bits mainly serve as flags related to SRM1 operation. These bits retain
their status even after the SRM1 power supply has been turned off or when
operation begins or stops. For details on the various bit functions, refer to rel-
evant sections in this manual or to Appendix C Memory Areas.
When the SRM1 is linked one-to-one with another SRM1, a CQM1, an CPM1/
CPM1A or a C200HS PC, these bits are used to share data. For details, refer
to page 104.
LR bits can be used as work bits when not used for data links.
This area is used to manage timers and counters created with TIM, TIMH(15),
CNT, and CNTR(12). The same numbers are used for both timers and
counters and each number can be used only once in the user program. Do not
use the same TC number twice even for different instructions.
TC numbers are used to create timers and counters, as well as to access
Completion Flags and present values (PVs). If a TC number is designated for
word data, it will access the present value (PV); if it is used for bit data, it will
access the Completion Flag for the timer/counter.
Refer to instructions beginning on page 212 for details on timers and
counters.
Section 3-3
147