4. Functions
CNT-3204MT-LPE
57
Figure 4.15. Example 3
Counter error
Counter errors are classified into two types: digital filter error and abnormal input error.
Digital filter error
A digital filter error occurs when a signal faster than the digital filter setting is input to phase A or phase
B. Notification of the error is via a status (latch/clear), interrupt, or external output (one-shot pulse).
The board monitors the input signal level for digital filter errors using the filter source clock which has a
period of 1/2 the setting value. The digital filter error is detected when the same level cannot be detected
for two or more consecutive times.
However, a filter error does not occur if the frequency of the input clock is equal to or close to an
integer multiple of the filer source clock.
The following are possible causes for a digital filter error.
-
When a signal faster than the digital filter setting is input
-
Noise is generated.
Figure 4.16. Filter error (Set to 0.2 µsec)
0
0
0
0
0
0
0
0
0
0
0
0
1
0
1
0
1
0
1
0
1
0
1
0
1
1
0
0
0
0
1
1
1
1
0
0
100nsec
Even when the input signal is less than 200 nsec,
no filter error occurs as long as the input sig
nal frequency is
an integer multiple of the source clock frequency.
When the signal is less than 200 nsec, a filter error is reported.
When the signal is not less than 200 nsec,
counting is performed normally.
Filter source clock
Phase-A/Phase-B
input signal
50nsec
Phase-A/Phase-B
input signal
Phase-A/Phase-B
input signal
Summary of Contents for CNT-3204MT-LPE
Page 7: ...vi CNT 3204MT LPE ...
Page 15: ...1 Before Using the Product 8 CNT 3204MT LPE ...
Page 29: ...2 Setup 22 CNT 3204MT LPE 3 Click on the End button to finish condition setting Click on End ...
Page 45: ...3 External Connection 38 CNT 3204MT LPE ...
Page 69: ...4 Functions 62 CNT 3204MT LPE ...
Page 73: ...5 About Software 66 CNT 3204MT LPE ...
Page 78: ......
