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MELSEC-Q
1 OVERVIEW
1.1 Features
The features of the QD62(E/D) are as follows:
(1) Counting can be performed in a wide range (The count value can be
expressed within the range between -2147483648 and 2147483647)
• A count value is stored in 32-bit signed binary.
• The number of channels is 2.
(2) The maximum counting speed can be changed
The maximum speed of the QD62D can be changed by selecting from among
500 k, 200 k, 100 k and 10 k, while that of the QD62 and QD62E can be selected
from among 200 k, 100 k and 10 k. This allows an error-free count even with
gradual rise/fall pulses.
(3) Pulse input can be selected
The pulse input can be selected from 1 phase multiple of 1, 1 phase multiple of 2,
2 phase multiple of 1, 2 phase multiple of 2, 2 phase multiple of 4, CW and CCW.
(4) Counter format can be selected
Either one of the following counter formats can be selected.
(a) Linear counter format
A count from -2147483648 to 2147483647 is possible and if the count
exceeds the range, an overflow will be detected.
(b) Ring counter format
This type counts pulses repeatedly within the range between the ring
counter upper limit and the ring counter lower limit.
(5) Coincidence output is possible
Any channel coincidence output point can be preset to compare with the present
counter value to output the ON/OFF signal output, or to start an interrupt program.
(6) Selection can be made from four counter functions
One of the following four functions can be selected.
(a) Count disable function
This function stops counting pulses by inputting a signal while CH Count
enable command (Y4, YC) is on.
(b) Latch counter function
This function latches the present value of the counter when the signal was
input.
(c) Sampling counter function
This function counts the pulses that were input within the preset time period
from the signal input.
(d) Periodic pulse counter function
This function stores the present and previous values of the counter at each
preset time interval while the signal is being input.
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