Step Flag; First Cycle Flag; Clock Pulse Bits - Omron SYSMAC CVM1 Series Operation Manual

Auxiliary Area
! Caution
Carry Flag, CY
Greater Than Flag, GR
Equals Flag, EQ
Less Than Flag, LE
Negative Flag, N
Overflow Flag, OF
Underflow Flag, UF
Caution
!

3-6-56 Step Flag

3-6-57 First Cycle Flag

3-6-58 Clock Pulse Bits

58
These flags are all reset when the END instruction is executed, and therefore
cannot be monitored from a Programming Device.
Refer to 5-14 Shift Instructions, 5-16 Comparison Instructions, 5-18 BCD Cal-
culation Instructions, and 5-19 Binary Calculation Instructions for details.
Bit A50004 is turned ON when there is a carry in the result of an arithmetic opera-
tion or when a rotate or shift instruction moves a "1" into CY. The content of CY is
also used in some arithmetic operations, e.g., it is added or subtracted along
with other operands. This flag can be set and cleared from the program using the
SET CARRY and CLEAR CARRY instructions. This Flag is also used by the I/O
READ and I/O WRITE instructions. Refer to page 378 for details.
Bit A50005 is turned ON when the result of a comparison shows the first of two
operands to be greater than the second.
Bit A50006 is turned ON when the result of a comparison shows two operands to
be equal or when the result of an arithmetic operation is zero.
Bit A50007 is turned ON when the result of a comparison shows the first of two
operands to be less than the second.
Bit A50008 is turned ON when the highest bit in the result of a calculation is ON.
Bit A50009 is turned ON when the absolute value of the result is greater than the
maximum value that can be expressed.
Bit A50010 is turned ON when absolute value of the result is less than the mini-
mum value that can be expressed.
The previous seven flags are cleared when END(001) is is executed.
Bit A50012 is turned ON for one cycle when step execution is started with the
STEP(008) instruction.
When ladder-only programming is used, bit A50015 turns ON when PC opera-
tion begins and then turns OFF after one cycle of the program. The First Cycle
Flag is useful in initializing counter values and other operations. An example of
this is provided in 5-13 Timer and Counter Instructions.
Note Do not use A50015 to control execution of differentiated instructions. The
instructions will never be executed.
Four clock pulses are available to control program timing. Each clock pulse bit is
ON for the first half of the rated pulse time, then OFF for the second half. In other
words, each clock pulse has a duty factor of 50%.
Pulse width 0.1 s
Bit A50100
These clock pulse bits are often used with counter instructions to create timers.
Refer to 5-13 Timer and Counter Instructions for an example of this.
0.2 s 1.0 s
A50101 A50102
Section 3-6
0.02 s
A50103