Master Control (Start)
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 | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| n | - | - | - | - | - | - | - | - | - | - | - | - | - | - | ✓ |
Supported Flags
| Flag | Bit | Support |
|---|---|---|
| Error | F11.0 | ✓ |
| Zero | F11.1 | - |
| Carry | F11.2 | - |
Number of Steps
| Steps |
|---|
| 1 |
Operands
| Operand | Description |
|---|---|
| n | The only operand. Entries are only constants. This is the identifier for the start of the master control area. If nesting master control, the value range is 0 ~ 7. |
Notice
Notice
A compile error will occur when the number of nests, n, is greater than 8.
Execution Behavior
Instruction Behavior
The MC instruction behaves as follows:
- MC n indicates the start of the master control area.
- This allows for circuit switching efficiency.
- When the execution condition of the MC instruction is ON (1), master control starts operation.
- When master control starts, the program is executed from MC n to MCR n where n is the same number.
- When the execution condition of the MC instruction is OFF (0), master control does NOT start operation and the MCR instruction is not executed.
- The MC and MCR instructions can be nested.
- MC ~ MCR can be nested up to 8 levels (0 ~ 7).
- If MC ~ MCR instructions are nested in other MC ~ MCR, the nesting number, n, is available from lower to higher with the MC instruction and higher to lower with the MCR instruction.
- Please refer to Master Control Example 1.
- When nesting is composed in reverse, a compile error occurs.
Master Control Area
- Master Control is defined as a control area within the ladder logic for executing certain parts of the ladder logic code.
- Master Control will execute from MC n through MCR n where n is a constant.
- If MC ~ MCR instructions are nested in other MC ~ MCR, the nesting number, n, is available from lower to higher with the MC instruction and higher to lower with the MCR instruction.
- MCR with the lowest nesting number can terminate all master controls when:
- MCR instructions are nested in one place.
- There may be MC instructions with higher nesting numbers, n, within the MC ~ MCR area with the lowest nesting number, n.
