Function Switching] Switching Of Allocation And Functions Of Input Terminals; Cautions On Use - Mitsubishi Electric MELSEQ FX3S Series User Manual

FX Series Programmable Controllers
3S
User's Manual - Hardware Edition

10.9.2 [Function switching] switching of allocation and functions of input terminals

When the counters C248 and C253 are combined with the auxiliary relays (M8388), the allocation of the input
terminals and functions are changed.
Program the special auxiliary relays just before the counters.
High-speed counter type
C248 (OP)
C253 (OP)

10.10 Cautions on Use

• If the operation of a high-speed counter is triggered by a device such as a switch, the counter may
malfunction due to extra noise from switch chattering or contact bounce.
• The input filter of an input terminal for a high-speed counter in the main unit is automatically set to 10 μs
(X000, X001) or 50 μs (X002 to X007).
Accordingly, it is not necessary to use special data register D8020 (input filter adjustment).
The input filter for input relays not being used for high-speed counters remains at 10 ms (initial value).
• The input terminals X000 to X007 can be used for high-speed counters, input interruption, pulse catch,
SPD instruction, ZRN instruction and DSZR instruction and general-purpose inputs.
Take care not to overlap the input numbers.
• Make sure that the signal speed for high-speed counters does not exceed the response frequency
described above. If an input signal exceeds the response frequency, a WDT error may occur, or the
communication functions such as a parallel link may malfunction.
• The response frequency changes depending on the number of used counters, but the input filter value is
fixed to 10 μs (X000, X001) or 50 μs (X002 to X007). Note that noise above the response frequency may
be counted depending on the filter value of the used input.
Function switching method
M8388
M8392
K
C248
M8388
M8392
K
C253
→ For programming details, refer to the Programming Manual.
10 Use of High-speed Counters
10.10 Cautions on Use
Details of change
• Reset input is not given.
• Reset input is not given.
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