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 less than S2.
LDE Execution Condition
When the result of the instruction execution of the expression D26 < D28 (3.300000 < 2.300000) is FALSE, the coil, Y1.6, is deenergized.
When the result of the instruction execution of the expression D26 < D28 (-3.300000 < 2.300000) is TRUE, the coil, Y1.6, is energized.
Memory Monitor
ANDE Execution Condition
When the result of the instruction execution of the expression D30 < D32 (2.200000 < 1.100000) is FALSE, and the contact, M0.0 is ON (1), the coil, Y1.7, is deenergized.
When the result of the instruction execution of the expression D30 < D32 (1.000000 < 1.100000) is TRUE, and the contact, M0.0 is ON (1), the coil, Y1.7, is energized.
Memory Monitor
ORE Execution Condition
When the result of the instruction execution of the expression D34 < D36 (1.120000 < 1.100000) is FALSE, or the contact, M0.1 is ON (1), the coil, Y1.8, is energized.
When the result of the instruction execution of the expression D34 < D36 (-1.120000 < 1.100000) is TRUE, and the contact, M0.1 is OFF (0), the coil, Y1.8, is energized.
Memory Monitor
