152
FX
3U
/FX
3UC
Series Programmable Controllers
Programming Manual - Basic & Applied Instruction Edition
6 What to Understand before Programming
6.5 General Rules for Applied Instructions
Limitation in simultaneous drive of instructions
Some applied instructions can be programmed twice or more, but the number of simultaneous drive is limited.
Even in instructions not shown below, if two or more instructions are driven at the same time for a same I/O
number, it is regarded as double outputs. In some combinations of instructions, the operation may be
complicated, or the instructions cannot be executed.
For the details, refer to the caution described in each instruction page.
For combinations of instructions, refer to "6.4 Mutual relationship among program flow control instructions".
1. Positioning instructions
Do not drive FNC 57 (PLSY), FNC 58 (PWM), FNC 59 (PLSR), FNC150 (DSZR), FNC151 (DVIT), FNC156
(ZRN), FNC157 (PLSV), FNC158 (DRVI) and FNC159 (DRVA) instructions at the same time for the same
output number.
2. High speed processing instructions
In FNC 53 (HSCS), FNC 54 (HSCR) and FNC 55 (HSZ) instructions (including FNC280 (HSCT) instruction),
make sure that up to 32 instructions are driven at the same time. [FNC280 (HSCT) instruction can be used
only once.]
Note that each of "FNC280 (HSCT) instruction", "table high speed comparison mode of FNC 55 (HSZ)
instruction)" and "frequency control mode of FNC 55 (HSZ) instruction" can be used only once respectively.
3. External device communication instructions
• In FNC 80 (RS) and FNC 87 (RS2) instructions, do not drive two or more instructions at the same time for
the same port.
• It is impossible to combine and use FNC 80 (RS), FNC 87 (RS2), FNC270 (IVCK), FNC271 (IVDR),
FNC272 (IVRD), FNC273 (IVWR) and FNC274 (IVBWR) instructions for the same port.
• In FNC270 (IVCK), FNC271 (IVDR), FNC272 (IVRD), FNC273 (IVWR) and FNC274 (IVBWR) instructions,
two or more instructions can be driven at the same time for the same port.