Mitsubishi Electric MELSEC FX3U Programming Manual page 111

FX /FX /FX Series Programmable Controllers
3G 3U 3UC
Programming Manual - Basic & Applied Instruction Edition
5. High speed counter device list
Classification
Hardware
counter
1-phase
1-count
input
Software counter
Hardware
counter
1-phase
2-count
input
Software counter
Hardware
counter
2-phase
2-count
input
Software counter
*1. They are handled as software counters depending on the operating condition. When they are handled
as software counters, they have limitations on both maximum response frequency and total
frequency.
*2. Cautions on wiring should be considered for these high speed counters.
*3. C244, C245 and C248 are usually used as software counters, but can be used as hardware counters
C244 (OP), C245 (OP) and C248 (OP) by combining a special auxiliary relay (M8388, M8390 to
M8392).
*4. 2-phase 2-input counter is usually 1 edge count counter, but can be used as a 4 edge count counter by
combining a special auxiliary relay (M8388, M8198 or M8199).
*5. The external reset input is usually reset by turning ON, but can be changed to be reset by turning OFF
by combining special auxiliary relays (M8388 and M8389).
→ For the method to change the logic of the external reset input, refer to Subsection 4.7.6.
*6. The counter C253 is usually used as a hardware counter, but can be used as the counter C253 (OP)
not equipped with reset input by combining special auxiliary relays (M8388 and M8392).
In this case, C253 (OP) is handled as a software counter.
Counter No. Edge count
*2
C235
*2
C236
*2
C237
*2
C238
*1
*2
C239
*2
C240
*3
C244(OP)
*3
C245(OP)
C241
C242
C243
*3
C244
*3
C245
*2
C246
*1
*2*3
C248(OP)
C247
*3
C248
C249
C250
*2
C251
*1
*2
C253
C252
*6
C253(OP)
C254
C255
→ For the wiring, refer to the Hardware Edition of the main unit.
→ For the method to switch the counter function, refer to Subsection 4.7.7.
→ For the method to use a 2-phase 2-input 4 edge count counter,
4.7 High Speed Counter [C] (FX3U/FX3UC PLC)
External reset
Data length
input terminal
−
32-bit
bi-directional
−
counter
−
−
−
32-bit
bi-directional
−
counter
−
*4
1
*4
4
*4
1
*4
4
32-bit
*4
1
bi-directional
*4
4
counter
*4
1
*4
4
*4
1
*4
4
→ For the condition handled as software counters,
→ For the total frequency, refer to Subsection 4.7.10.
4 Devices in Detail
External start
input terminal
Not provided Not provided
*5
Not provided
Provided
*5
Provided
Provided
Not provided Not provided
*5
Not provided
Provided
*5
Provided
Provided
Not provided
Not provided
*5
Provided
*5
Provided
Not provided
Not provided
*5
Provided
Provided
refer to Subsection 4.7.9.
refer to Subsection 4.7.8.
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