59
Find the instruction
that requires deletion.
Confirm that this is the
instruction to be deleted.
Program After Deletion
Deleting an Instruction
0000
0000
OUT 0000
0000
OUT 0201
0208SRCH
OUT 0201
0207READ
AND NOT 0104
0207 DELETE?
AND NOT 0104
0207DELETE END
OUT 0201
0206READ
AND 0105
Address
Instruction
Operands
0000
LD
0100
0001
AND NOT
0101
0002
LD
0201
0003
AND NOT
0102
0004
OR LD
---
0005
AND
0103
0006
AND
0105
0007
AND NOT
0104
0008
OUT
0201
4-7
Controlling Bit Status
There are five instructions that can be used generally to control individual bit
status. These are the OUTPUT or OUT, OUTPUT NOT or OUT NOT, DIF-
FERENTIATE UP, DIFFERENTIATE DOWN, and KEEP instructions. All of
these instruction appear as the last instruction in an instruction line and take
a bit address for an operand. Although details are provided in
5-6 Bit Control
Instructions, these instructions are described here because of their impor-
tance in most programs. Although these instructions are used to turn ON and
OFF output bits in the IR area (i.e., to send or stop output signals to external
devices), they are also used to control the status of other bits in the IR area
or in other data areas.
4-7-1
DIFFERENTIATE UP and DIFFERENTIATE DOWN
DIFFERENTIATE UP (DIFU(13)) and DIFFERENTIATE DOWN (DIFD(14))
instructions are used to turn the operand bit ON for one cycle at a time. The
DIFFERENTIATE UP turns ON the operand bit for one cycle after the execu-
tion condition when it goes from OFF to ON; the DIFFERENTIATE DOWN
instruction turns ON the operand bit for one cycle after the execution condi-
tion when it goes from ON to OFF.
0000
0001
DIFU(13) 0500
DIFD(14) 0501
Address
Instruction
Operands
0000
LD
0000
0001
DIFU(13)
0500
Address
Instruction
Operands
0000
LD
0001
0001
DIFD(14)
0501
Controlling Bit Status
Section 4-7
Summary of Contents for SYSMAC C20K
Page 1: ...Cat No W146 E1 5 Programmable Controllers SYSMAC C20K C28K C40K C60K ...
Page 2: ...K type Programmable Controllers OPERATION MANUAL Revised July 1999 ...
Page 3: ...iv ...
Page 5: ...vi ...
Page 19: ...7 SECTION 2 Hardware Considerations 2 1 Introduction 2 2 Indicators 2 3 PC Configuration ...