User manual

Mode 50
Pulse Catch Input
Installation and
Safety Guidelines
7–3
Pulse Catch Input
DL205 High Speed Counter
Interface Manual, 2nd Ed, Rev. A
The following example will help to explain the Pulse Catch Mode.
Counting pulses in Mode 50 (Pulse Catch Input)
CNT CT1
K9999
Counting input pulses in the user program has some problems to be considered.
X0
C0
Input
Update
Solve user logic
Output
Update
Pulse input
to Point 00
Input
Update
Solve user logic
Output
Update
Input
Update
Solve user logic
Output
Update
X0
[Case 1] This is okay.
In this case, the pulse can be counted correctly.
Input
Update
Solve user logic
Output
Update
Pulse input
to Point 00
Input
Update
Solve user logic
Output
Update
Input
Update
Solve user logic
Output
Update
X0
Both of these pulses are counted as one pulse.
[Case 2] This is not okay.
Input
Update
Solve user logic
Output
Update
Pulse input
to Point 00
Input
Update
Solve user logic
Output
Update
Input
Update
Solve user logic
Output
Update
X0
Both of these pulses are also counted as one pulse.
[Case 3] This also is not okay.
To count the pulses correctly, Mode 10 or Mode 20 should be used.
Pulse Catching
Explained