How to Use the Step Ladder Program Block
Appendix 1
210
List of Sequence Control Instructions
: Can be used
: Cannot be used
Command
Command
code
Ladder symbol
Operand
Description
Input
conditions
In logic
sequence
In step
sequence
STEP
21
STEP
Step number
Step
number
STEP declares the step
number, and has no input
conditions (is a direction
connection to the bus).
Any numbers in the range
00 to 99 are used as the
step number, and are
placed in ascending order.
1)
Logic sequence: The
step number is fixed at
00, and is functional at
all times. Declaration of
step number 00 can be
omitted.
2)
Step sequence: When
the step number is
within the range 01 to
99, only one of the
steps is functional.
When the program is
started, step number
01 is functional.
Not required
BLOCK
SET
22
(
)
BS
Block
address/
step
number
When the input conditions
turn ON, operation of the
specified step number of
the Step Ladder Program
block at the specified block
address (400 to 499) is
started.
Run/stop command S1 of
the specified block turns
automatically 1 (ON).
Operation of currently
executing steps in already
operating Step Ladder
Program blocks is
interrupted, and execution
of the program jumps to the
specified step.
Required
BLOCK
RSET
23
(
)
BR
Block
address
When the input conditions
turn ON, operation of the
Step Ladder Program block
is stopped at the specified
block address (400 to 499).
Run/stop command S1 of
the specified block
automatically turns 0
(OFF).
Required