5 - 9                         5 - 9 
MELSEC-Q
5   DETAILS AND SETTING OF FUNCTIONS 
 
5.3 Input Pulse Value 
The pulse number entered into the QD60P8-G is stored into the "input pulse 
value" of the buffer memory. This value is counted when the count enable (Y18 
to Y1F) is ON. 
 
The input pulse value is not converted into the unit pulse number by the pre-scale 
function (refer to Section 5.6), unlike the "sampling pulse number" and 
"accumulating count value" of the buffer memory. If an overflow error occurs, the 
value is counted when the count enable (Y18 to Y1F) is ON. 
The count type of the input pulse value is a ring counter of 0 to 2147483647. 
 
Input pulse 
alue
2147483647 0 12321474836462147483600
Input pulse count value of 2147483647 
incremented by 1 turns to 0.
to
 
 
Buffer memory address 
Item Read value 
CH1 CH2 CH3 CH4 CH5 CH6 CH7 CH8 
Input pulse value  0 to 2147483647 
10 
11 
42 
43 
74 
75 
106 
107 
138 
139 
170 
171 
202 
203 
234 
235 
 
The buffer memory addresses for resetting the input pulse values are as follows. 
 
Buffer memory address 
Item 
CH1 CH2 CH3 CH4 CH5 CH6 CH7 CH8 
Counter reset request  13  45  77  109  141  173  205  237 
 
 
POINT 
 
•  The update timing of the input pulse value is fixed at 10ms. Therefore, take care 
when using the module as a counter. (Refer to Section 5.9) 
•  When reading the input pulse value, always read two words together. 
If it is read in single word unit, a wrong count value may be read due to a data 
mismatch between the lower word and upper word when the count value is 
updated halfway during read.