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 only BOOL data registers. This is the data register to find the status bit. |
| S2 | The second operand. Entries are WORD data registers or constants. This is the bit value number to find the ON or OFF status of. The value range is 0 ~ 15. |
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.
Instruction Behavior
The BT instruction as an execution condition behaves as follows: – The referred status of bit data assigned to the data register, S2, is used as a contact – With the referred status of bit data, the BT instruction starts a contact A operation. – An ON or OFF execution condition is created based on the ON status (1) of the specified bit, S2, in the BOOL data register, S1. – The BT instruction is connected to the bus bar or used at the beginning of a logic block. – The value range of the specified bit, S2, is 0 ~ 15. – If the specified bit value, S2, is greater than 16, the remainder from S2 ÷ 16 is the equivalent. – Example: if S2 = 17, the remainder is 1. This is the same as S2 = 1.
Ladder Diagram Examples
LD Execution Condition Example
The BT instruction can be used as a LD execution condition for a contact A operation.
When the value of the specified bit, S2, is 0, the BT instruction is powered OFF.
Memory Monitor 1
When the value of the specified bit, S2, is 1, the BT instruction is powered ON.
The coil, Y1.0, is energized.
Memory Monitor 2
AND Execution Condition Example
The BT instruction can be used as an AND execution condition for a contact A operation.
When the open contact, M1.0, is powered OFF AND the value of the specified bit, S2, is 0, the coil, Y1.0, is deenergized.
When the open contact, M1.0, is powered ON AND the value of the specified bit, S2, is 0, the coil, Y1.0, is deenergized.
When the open contact, M1.0, is powered ON AND the value of the specified bit, S2, is 1, the coil, Y1.0, is energized.
Memory Monitor
OR Execution Condition Example
The BT instruction can be used as an OR execution condition for a contact A operation.
When the open contact, M1.0, is powered OFF OR the value of the specified bit, S2, is 0, the coil, Y1.0, is deenergized.
When the open contact, M1.0, is powered ON the coil, Y1.0, is energized.
When the value of the specified bit, S2, is 1, the coil, Y1.0, is energized.
When the open contact, M1.0, is powered ON OR the value of the specified bit, S2, is 1, the coil, Y1.0, is energized.
Memory Monitor
