Download FXCPU Structured Programming Manual

FXCPU Structured Programming Manual
2 Devices in Detail
[Device & Common]
2.7 High Speed Counter [C]
2) In FX3G/FX3GC PLCs
Counter type
Response
Software counter frequency
C235, C236, C238,
1-phase C239, C241
1-counting
C237, C240, C242,
input
C243, C244, C245
When DHSCS, DHSCR or DHSZ
instruction is used
200 kHz - (Number of positioned axes*1 + Number of
pulse width/period measurement inputs) × 40 kHz
60 kHz - (Number of positioned axes*1 × 5 kHz)
(Number of pulse width/period measurement
inputs × 20 kHz)
60kHz
10kHz
1-phase C246, C248(OP)
2-counting C247, C248, C249,
input
C250
60kHz
2-phase C251, C253(OP)
2-counting C252, C253, C254,
input
C254(OP), C255
30kHz
*1.
Overall frequency determined by condition of instructions used
When DHSCS, DHSCR or DHSZ
instruction is not used
10kHz
5kHz
Number of axes used in the following positioning instructions:
PLSY, PLSR , DSZR , DTBL , ZRN , PLSV , DRVI , DRVA
• Calculation of the total frequency
The total frequency is calculated using the following expression:
Total frequency ≥ (Sum of frequency used by 1-phase counters) + (Sum of frequency
used by 2-phase counters)
• Calculation example
Example1: When DHSCS, DHSCR or DHSZ instruction is not used, and instructions related to positioning
(DRVI instruction [Y000] and DRVA instruction [Y001]) are used
Overall frequency: 200 kHz - (2 axes × 40 kHz) = 120 kHz
<Counter No.>
C235 (1-phase 1-counting) :
C236 (1-phase 1-counting) :
C237 (1-phase 1-counting) :
C253 (2-phase 2-counting) :
<Contents of use>
50 kHz is input.
50 kHz is input.
10 kHz is input.
5 kHz is input.
Total115 kHz
120 kHz (Overall frequency)
Example2: When DHSCS, DHSCR or DHSZ instruction is not used, and instructions related to positioning
(DRVI instruction [Y000] are used, Number of pulse width/pulse period measurement
inputs(X003)
Overall frequency: 200 kHz - (1 axes + 1 input) × 40 kHz = 120 kHz
<Counter No.>
C235 (1-phase 1-counting) :
C236 (1-phase 1-counting) :
<Contents of use>
50 kHz is input.
50 kHz is input.
Total100 kHz
86
120 kHz (Overall frequency)