Comparison Uses
There are three types of comparison uses:
- LDE (Ladder Diagram)
- ANDE
- ORE
The following compare instructions can be used as a:
- REAL standalone execution condition (LDE)
- REAL and execution condition (ANDE)
- REAL or execution condition (ORE)
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 REAL data registers or constants. The value range is -1.7014118e+38 ~ 3.4028237e+38 (2-127 ~ 2128). Only REAL values will be compared. Only signed or Hexadecimal values will be compared. |
| S2 | The second operand. Entries are signed REAL data registers or constants. The value range is -1.7014118e+38 ~ 3.4028237e+38 (2-127 ~ 2128). Only REAL values will be compared. Only signed or Hexadecimal values will be compared. |
Float Representation
| Mantissa | Exponent | Sign |
|---|---|---|
| Bit 0 ~ Bit 22 | Bit 23 ~ Bit 30 | Bit 31 |
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
E>=
The E>= instruction compares a REAL value, S1, to another REAL value, S2, and executes if S1 is greater than or equal to S2.
LDE Execution Condition
When the result of the instruction execution of the expression D26 ≥ D28 (0.000000 ≥ 2.000000) is FALSE, the coil, Y4.6, is deenergized.
When the result of the instruction execution of the expression D26 ≥ D28 (2.000000 ≥ 2.000000) is TRUE, the coil, Y4.6, is energized.
Memory Monitor
ANDE Execution Condition
When the result of the instruction execution of the expression D30 ≥ D32 (-1.700000 ≥ 1.700000) is FALSE, and the contact, M0.0 is ON (1), the coil, Y4.7, is deenergized.
When the result of the instruction execution of the expression D30 ≥ D32 (2.700000 ≥ 1.700000) is TRUE, and the contact, M0.0 is ON (1), the coil, Y4.7, is energized.
Memory Monitor
ORE Execution Condition
When the result of the instruction execution of the expression D34 ≥ D36 (1.800000 ≥ 2.000000) is FALSE, or the contact, M0.1 is ON (1), the coil, Y4.8, is energized.
When the result of the instruction execution of the expression D34 ≥ D36 (2.400000 ≥ 2.000000) is TRUE, and the contact, M0.1 is OFF (0), the coil, Y4.8, is energized.
Memory Monitor
