Conditions For Hardware Counter To Be Handled As Software Counter; Conditions Under Which Counters Are Handled As Software Counters; Method Of Confirming Operation Status Of Counters - Mitsubishi FX3U SERIES User Manual

FX Series Programmable Controllers
3U
User's Manual - Hardware Edition
11.8

Conditions for Hardware Counter to be Handled as Software Counter

The high-speed counters are classified into hardware counters and software counters.
Some hardware counters are handled as software counters depending on the operating conditions.
In this case, use hardware counters within the range of maximum response frequency and total frequency
determined for software counters.

11.8.1 Conditions under which counters are handled as software counters

The hardware counters can perform counting with the hardware of FX
However, under the following conditions, they are handled as software counters.
When using them in the condition below, the maximum response frequencies and overall frequency of the
counters are considered to be the same as those of other software counters.
Hardware
counter No.
C235
C236
C237
C238
C239
C240
C244(OP)
C245(OP)
C246
C248(OP)
C251
C253

11.8.2 Method of confirming operation status of counters

The high-speed counter mode, hardware or software, can be confirmed by checking whether the operation
status (M8380 to M8387) is on or off.
194
Conditions under which counters are handled as software counters
When DHSCS (FNC53), DHSCR (FNC54), DHSZ (FNC55) or DHSCT (FNC280) instruction is used
for a hardware counter number, the hardware counter is handled as a software counter.
Ex.: C235
DHSCS K100
In this case, C235 works as a software counter.
When the index register is used for the counter number designated by DHSCS (FNC53), DHSCR
(FNC54), DHSZ (FNC55) or DHSCT (FNC280) instruction, all hardware counters are handled as
software counters.
Ex.: C235Z0
DHSCS K100 C235Z0 Y000
When the logic is reversed by the external rest input signal logic change function, C253 (hardware
counter) is switched to a software counter.
Ex.: The logic of the external reset input signal of C253 is inverted.
M8388
M8389
C253
→ For the list of operation status of high-speed counters, refer to Subsection 11.11.1.
11 Use of High-speed Counters (C235 to C255)
11.8 Conditions for Hardware Counter to be Handled as Software Counter
C235
K
C235 Y000
→ For the inversion of the logic of external reset input signal,
K
regardless of the overall frequency.
3U
refer to Subsection 11.11.2.