![background image](http://html1.mh-extra.com/html/omron/zen-soft01-v4-12-2008/zen-soft01-v4-12-2008_operation-manual_744252032.webp)
14
Circuit Diagrams and Ladder Programs
Section 2-1
∗
Calendar
timers
Turns ON/OFF between specified
dates.
Yes
No
Q
CPU Unit
output bits
Correspond to
CPU Unit output
terminals.
Can specify
Normal output
([), Set (S)/
Reset (R), or
Alternate (A)
operation.
Yes
Yes
Y
Expansion I/O
Unit output bits
Correspond to
Expansion I/O
Unit output
terminals.
Yes
Yes
M
Work bits
Bits that can be
used in the
ladder program.
Yes
Yes
H
Holding bits
Bits that
maintain ON/
OFF status at
power
interruptions
and can be used
in the ladder
program.
Yes
Yes
T
Timers
Timers can be used for ON delay
(X), OFF delay (
■
), One-shot pulse
(O), Flashing pulse (F), or Twin (W)
operation.
Yes
Yes
#
Holding timers
Timers that maintain the present
value at power interruptions. (ON
delay operation only.)
Yes
Yes
C
Counters
Incremental or decremental
counters
Yes
Yes
F
8-digit Counter
Incremental or decremental
counter with 8-digit capacity.
Yes
Yes
D
Display bits
Display character strings, month/
day, time, timer/counter present
value, or analog conversion value
on CPU Unit LCD display.
No
Yes
Symbol
Name
Function
Usable as input
condition
Usable as
output
Z184-E1-04.book Page 14 Thursday, November 20, 2008 4:25 PM