Comparison Uses
There are three types of comparison uses:
- LD (Ladder Diagram)
- AND
- OR
The following compare instructions can be used as a:
- WORD standalone execution condition (LD)
- WORD and execution condition (AND)
- WORD or execution condition (OR)
Instruction Parameters
Supported PLC Series
| PLC-AES | PLC-FB | PLC-ES |
|---|---|---|
| ✓ | ✓ | ✓ |
Supported Data Registers
| M | X | Y | K | L | F | T | C | S | Z | R | Q | D | @D | Constant | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| S1 | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ | – | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ |
| S2 | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ | – | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ |
Supported Flags
| Flag | Bit | Support |
|---|---|---|
| Error | F11.0 | ✓ |
| Zero | F11.1 | – |
| Carry | F11.2 | – |
Number of Steps
| Steps |
|---|
| 3 |
Operands
| Operand | Description |
|---|---|
| S1 | The first operand. Entries are signed WORD data registers or constants. The signed value range is -32,768 ~ 32,767 (216). The Hexadecimal value range is H0000 ~ HFFFF. Only WORD values will be compared. Only signed or Hexadecimal values will be compared. |
| S2 | The second operand. Entries are signed WORD data registers or constants. The signed value range is -32,768 ~ 32,767 (216). The Hexadecimal value range is H0000 ~ HFFFF. Only WORD values will be compared. Only signed or Hexadecimal values will be compared. |
Notice
Error Flag (F11.0) Notice
The error flag, F11.0, will be ON for one scan when the address of the data register assigned by @D exceeds the range of the data register, D. The range of the data register, D, is dependent on the CPU type.
Ladder Diagram Examples
<=
The \<= instruction compares a WORD value, S1, to another WORD value, S2, and executes if S1 is less than or equal to S2.
LD Execution Condition
When the result of the instruction execution of the expression D0 ≤ D2 (0 ≤ -32,461) is FALSE, the coil, Y2.0, is deenergized.
When the result of the instruction execution of the expression D0 ≤ D2 (-24,444 ≤ -23,461) is TRUE, the coil, Y2.0, is energized.
Memory Monitor
AND Execution Condition
When the result of the instruction execution of the expression D5 ≤ D7 (23,232 ≤ -4,562) is FALSE, and the contact, M0.0 is ON (1), the coil, Y2.1, is deenergized.
When the result of the instruction execution of the expression D5 ≤ D7 (-23,561 ≤ 32,562) is TRUE, and the contact, M0.0 is ON (1), the coil, Y2.1, is energized.
Memory Monitor
OR Execution Condition
When the result of the instruction execution of the expression D10 ≤ D12 (2,564 ≤ -1,562) is FALSE, or the contact, M0.1 is ON (1), the coil, Y2.2, is energized.
When the result of the instruction execution of the expression D10 ≤ D12 (-13,564 ≤ -1,562) is TRUE, and the contact, M0.1 is OFF (0), the coil, Y2.2, is energized.
Memory Monitor
