10 Use of High-speed Counters
97
FX3S Series Programmable Controllers
User's Manual - Hardware Edition
1
Introduction
2
Features and
Part Names
3
Product
Introduction
4
Specifications
5
Version and
Peripheral
Devices
6
System
Configuration
7
Installation
8
Preparation and
Power Supply
Wiring
9
Input Wiring
10
High-Speed
Counters
10.10 Cautions on Use
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.
10.10 Cautions on Use
For programming details, refer to the Programming Manual.
• 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 s
(X000, X001) or 50 s (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 s (X000, X001) or 50 s (X002 to X007). Note that noise above the response frequency may
be counted depending on the filter value of the used input.
High-speed counter type Function switching method Details of change
C248 (OP) • Reset input is not given.
C253 (OP) • Reset input is not given.
M8388
M8392
C248
K
M8388
M8392
C253
K