Somat eDAQlite, Руководство пользователя

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I2773-4.
4
en 137
Somat eDAQ
lite
Minimum Frequency Limit
Specify the desired minimum frequency limit for the Pulse Counter. If there is no new
pulse within the period (1/
f
min
), the channel outputs this frequency value.
NOTE
The minimum frequency limit parameter provides a solution when a pulse train stops.
For example, if a 50 Hz pulse train stops, the Pulse Counter output remains at 50 Hz
until there is a new pulse frequency.
7.2.6 Directional Velocity
The Directional Velocity channel generates a signed velocity output from two input
channels. One input channel is the unsigned velocity; the second input channel is a
position channel and sets the sign of the output channel.
The sign of the output channel is determined from the position channel as follows. If
the position on the current data sample is greater than the position on the previous
data sample, the sign is positive. If the position on the current data sample is less than
the position on the previous data sample, the sign is negative. If the position on the
current data sample is equal to the position on the previous data sample, the sign
retains its current value.
Input Channel
The velocity input channel data type must be 32-bit float. The direction input channel
data type must be either 32-bit float or 32-bit integer.
Output Data Type
The output channel data type is 32-bit float.
NOTE
It is strongly recommended that the direction input channel have a data type of 32-bit
integer, which is the raw data type of the quadrature decoder Pulse Counter channel.
Using a 32-bit float works only if the quadrature decoder output stays in the
approximate range of +/- 16000000 counts. The 32-bit integer data type allows use of
the full range of the quadrature decoder pulse channel of +2147483647 to
-2147483648 counts.
Check for Int32 Rollover
If the direction input channel is a 32-bit integer channel, use the int32 rollover check to
detect rollover of the signed 32-bit counter. If the counter jumps by more than
24000000 counts from one sample to the next, the eDAQ
lite
assumes that the
counter has rolled over. For example, if the counter jumps from +2100000000 to
-2140000000, the eDAQ
lite
detects a rollover and sets the sign to positive.
NOTE
Use the rollover check option on an as-needed basis as it does add some processing
overhead to the channel.
HBM: public