Mitsubishi QD60P8-G - 5.6 Pre-scale Function

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MELSEC-Q
5 DETAILS AND SETTING OF FUNCTIONS
5.6 Pre-scale Function
The pre-scale function converts the input pulse number into the unit pulse
number when its weight per pulse is a fraction.
The pre-scale function converts the input pulse value per count cycle into the unit
pulse number using the following operation formula. The result of conversion is
stored into the "sampling pulse number" of the buffer memory.
Sampling pulse number = input pulse value per count cycle
pre-scale
setting value
unit magnification
(The converted sampling pulse number is rounded down to the decimal point.)
Buffer memory address
Item Setting value
CH1 CH2 CH3 CH4 CH5 CH6 CH7 CH8
Pre-scale function
selection
(Unit magnification)
0: Pre-scale function invalid
1:
1
2:
0.1
3:
0.01
4: 0.001
5:
0.0001
6 38 70 102 134 166 198 230
Pre-scale setting value 0 to 32767 7 39 71 103 135 167 199 231
Input pulse value
(Input pulse value per count cycle)
570 600 580
Count
cycle
(Example)
If the input pulse value per count cycle is 1000, the pre-scale setting value is
5832, and the pre-scale function selection is 4.
Sampling pulse number = input pulse value per count cycle
pre-scale
setting value unit magnification
= 1000
5832 0.001
= 5832
This value is added to the accumulating count value.
POINT
• Note that if the pre-scale setting value is set to 0, the sampling pulse number
calculated with the above operation formula becomes 0, and it seems as if pulses
are not counted although they are actually counted.
• If the setting value is other than the above values, a pre-scale setting range
outside error (error code: 400) occurs. To clear the error, turn ON the error reset
request (Y8 to YF) of the corresponding channel. After this, set a correct value
and then turn ON the operating condition setting request flag (Y1).
• The settings are reflected on the module by turning ON the operating condition
setting request flag (Y1) after setting the values to the buffer memory.