3. Instruction Set
API
Mnemonic Operands Function
D
LD※
Contact Type Comparison
Type
OP
Bit Devices Word devices Program Steps
X Y M S K H KnX
KnY
KnM
KnS
T C D E F
LD※: 5 steps
DLD※: 9 steps
EX2/
SS2
SA2/
SE
SX2
EX2/
SS2
SA2/
SE
SX2
EX2/
SS2
SA2/
SE
SX2
Operands:
S
1
: Source device 1 S
2
: Source device 2
Explanations:
1. This instruction compares the content in S
1
and S
2
. Take API224 (LD=) for example, if the result
is “=”, the continuity of the instruction is enabled. If the result is “≠”, the continuity of the
instruction is disabled.
LD※ (※: =, >, <, <>, ≤, ≥) instruction is used for direct connection with left hand bus bar.
API No.
>
>
>
<>
<>
=
>=
>=
<
When the MSB (16-bit instruction: b15, 32-bit instruction: b31) of S
1
and S
2
is 1, the comparison
value will be viewed as a negative value in comparison.
When 32-bit counters (C200 ~ C254) are used in this instruction, make sure to adopt 32-bit
instruction (DLD※). If 16-bit instruction (LD※) is adopted, a “program error” will occur and the
ERROR indicator on the MPU panel will flash.
Program Example:
1. When the content in C10 = K200, Y20 = ON.
When the content in D200 > K-30 and X1 = ON, Y21 = ON and latched.
LD=
K200 C10
Y20
LD<=
D200 K-30
X1
SET
Y21