Count Up or Down
Instruction Parameters
Supported PLC Series
| XPnA/1R | XPnB | XPnE | XPnF | CP3A/B/P/U CP4A~D/U | CPnE | CPnF | BP | PLC-S |
|---|---|---|---|---|---|---|---|---|
| ✓ | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ |
Supported Data Registers
| M | X | Y | K | L | F | T | C | S | Z | R | Q | D | @D | Constant | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| c | - | - | - | - | - | - | - | ✓ | - | - | - | ✓ | - | - | - |
| v | - | - | - | - | - | - | - | - | - | ✓ | - | - | ✓ | - | ✓ |
Supported Flags
| Flag | Bit | Support |
|---|---|---|
| Error | F11.0 | ✓ |
| Zero | F11.1 | - |
| Carry | F11.2 | - |
Number of Steps
| Steps |
|---|
| 3 |
Operands
| Operand | Description |
|---|---|
| c | The first operand. Entries are only counter data registers. |
| v | The second operand. Entries are unsigned WORD data registers or constants. This is the value the counter contact, c, will energize at. The unsigned value range is 0 ~ 65,535 (216-1). The Hexadecimal value range is H0000 ~ HFFFF. Signed value entries will be treated as unsigned values. |
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 Z exceeds its range.
The valid range of the data register Z is Z128 ~ Z1023 when using Function Block implementation.
F11.0 turns ON when the value of the data register, CC, exceeds the range of 0 ~ 65,535 (unsigned).
Instruction Behavior
The CTUD instruction behaves as follows:
- The data register C assigned to c is a BOOL data register.
- CS and CC express the detailed value of the data register C assigned to c.
- CC is a WORD data register used for the current count value of c.
- CS is a WORD data register used for the count setting value of c.
- The value of CS is equal to the value of v.
- CS and CC express the detailed value of the data register C assigned to c.
- The value of CC increases or decreases each time the instruction is energized.
- There are 3 input signals for the instruction
- Count up signal
- Count down signal
- Reset signal
- The counter contact c turns ON when the value of CC is equal to or greater than v.
- The counter contact c will remain ON if either the count up or count down signal is energized and the value of CC is equal to or greater than v.
- There are 3 input signals for the instruction
- If the value of CC is 0, the instruction will not continue executing.
- If the reset signal is energized, CC will reset to 0.
- The counter contact c will turn OFF.
- If the reset signal is energized, CC will reset to 0.
- The counter contact assigned to c can be used as an A or B contact.
- When the counter contact meets the RST instruction, the contact is turned OFF (0), but the value of CC is maintained.