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 | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ | – | – | – | ✓ | – | ✓ | ✓ | ✓ | ✓ |
| S3 | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ | – | – | – | ✓ | – | ✓ | ✓ | ✓ | ✓ |
| D | ✓ | – | ✓ | ✓ | ✓ | – | – | – | – | ✓ | – | ✓ | ✓ | – | – |
Supported Flags
| Flag | Bit | Support |
|---|---|---|
| Error | F11.0 | – |
| Zero | F11.1 | – |
| Carry | F11.2 | – |
Number of Steps
| Steps |
|---|
| 5 |
Operands
| Operand | Description |
|---|---|
| S1 | The first operand. Entries are WORD data registers or constants. This is the air temperature in Celsius (°C). This value is 10 times the actual value. |
| S2 | The second operand. Entries are WORD data registers or constants. This is the wet-bulb temperature in Celsius (°C). This value is 10 times the actual value. |
| S3 | The third operand. Entries are WORD data registers or constants. This is the air pressure in millibar (hPa) units. |
| D | The fourth operand. Entries are only WORD data registers. This is where the relative humidity and dew point are stored. This requires 2 data registers. |
Notice
Relative Humidity Storage
The relative humidity is stored in the assigned WORD data register D, and the dew point is stored in the assigned WORD data register D+1.
Ladder Diagram Examples
REHUM
The REHUM instruction uses the air temperature, S1, wet-bulb temperature, S2, and air pressure, S3, to calculate the relative humidity and dew point and saves both in the assigned WORD data registers, D and D+1.
The REHUM instruction calculates the relative humidity using the following values: 25°C (D1), 20°C (D2), and 101.3hPA (D3).
When the contact, M4.0, is powered ON (1), the data register, D5, is set to 600 and the data register, D6, is set to 180. These are the relative humidity and dew point values, respectively.
Memory Monitor
REHUMP
The REHUMP one-shot instruction uses the air temperature, S1, wet-bulb temperature, S2, and air pressure, S3, to calculate the relative humidity and dew point and saves both in the assigned WORD data registers, D and D+1. Every time this instruction energizes, it executes only once.
The REHUM instruction calculates the relative humidity using the following values: 30°C (D10), 25°C (D11), and 101hPA (D12).
When the contact, M5.0, is powered ON (1), the data register, D14, is set to 700 and the data register, D15, is set to 240. These are the relative humidity and dew point values, respectively.
Memory Monitor
