Omron CPM1 - PROGRAMING MANUAL 02-2001 Programming Manual page 405

Step Instructions
00000
00001
00002
Address Instruction
00000 LD
00001 SNXT(09)
00002 STEP(08)
Step controlled by LR 1005.
00100 LD
00101 SNXT(09)
Precautions
Execution of a step is completed either by execution of the next SNXT(09) or by
turning OFF the control bit for the step (see example 3 below). When the step is
completed, all of the IR and HR bits in the step are turned OFF and all timers in
the step are reset to their SVs. Counters, shift registers, and bits used in
KEEP(11) maintain status. Two simple steps are shown below.
Step controlled by LR 1005
Step controlled by IR 20200
Operands
00000
LR 1005
LR 1005
00001
20200
Steps can be programmed in consecutively. Each step must start with STEP(08)
and generally ends with SNXT(09) (see example 3, below, for an exception).
When steps are programmed in series, three types of execution are possible:
sequential, branching, or parallel. The execution conditions for, and the position-
ing of, SNXT(09) determine how the steps are executed. The three examples
given below demonstrate these three types of step execution.
Interlocks, jumps, SBN(92), and END(01) cannot be used within step programs.
Bits used as control bits must not be used anywhere else in the program unless
they are being used to control the operation of the step (see example 3, below).
All control bits must be in the same word and must be consecutive.
If IR or LR bits are used for control bits, their status will be lost during any power
interruption. If it is necessary to maintain status to resume execution at the same
step, HR bits must be used.
Starts step execution
SNXT(09) LR 1005
STEP(08) LR 1005
SNXT(09) 20200
STEP(08) 20200
SNXT(09) 23000
Ends step execution
STEP(08)
Address Instruction
00102 STEP(08)
Step controlled by IR 20200.
00200 LD
00201 SNXT(09)
00202 STEP(08)
Section 7-14
1st step
2nd step
Operands
20200
00002
23000
---
387