Velocity, speed calculation

In addition to the counter value, the velocity and speed an also be measured. The measured values are determined through parameterization of the frequency values. The following limit values apply:

Measured value output

Measured value limit

Comment

lower

top

Frequency value

0.095 Hz

5 MHz

With 4-fold evaluation
Signal type: RS422 (diff. input)

0.095 Hz

1 MHz

With 4-fold evaluation
Signal type: TTL (single ended)

0.095 Hz

100 kHz

With 4-fold evaluation
Signal type: open collector

The frequency measurement is carried out as described in chapter "Frequency measurement (Frequency value)". In addition, the frequency value can be converted using the two indices 0x8000:1D "Frequency numerator" and 0x8000:1E "Frequency denominator".

Index (hex)

Name

Meaning

Default

8000:1D

Frequency numerator

Frequency numerator,
Factor for normalizing the frequency, e.g., the time unit

0x0000001 (1dec)

8000:1E

Frequency denominator

Frequency denominator,
Factor for normalizing the frequency, e.g., velocity calculation

0x0000001 (1dec)

Thus, the frequency can be normalized for application-specific speed measurement. The measured value continues to be output in the process data via "Frequency value" (index 0x6000:13).

The calculated measured value has the following relationship to the frequency:
Velocity, speed calculation 1:

Example for velocity calculation in m/s

The velocity value is determined as follows:
Velocity, speed calculation 2:

Index (hex)

Name

Example: velocity in m/s

Comment

8000:1D

Frequency numerator

0x00000C8 (200dec)

Travel path, conversion to m via "Frequency denominator"

8000:1E

Frequency denominator

0x003E8000 (4096000dec)

Specification of the number of periods over the travel path and conversion of the travel path to m

Example Calculation of speed frot in revolutions/s

Conversion into minutes depending on "Frequency scaling

Index (hex)

Entry

Index (hex)

Entry

0x8000:13 Frequency scaling

100dec: 0.01 Hz

0x8000:1D Frequency numerator

0x00001770 (6000dec)

1dec: 1 Hz

0x0000003C (60dec)

Velocity, speed calculation 3:

Index (hex)

Ex. Speed
frot in rpm

Comment

8000:1D Frequency numerator

0x0001770 (6000dec)

Output of the value in 0.01 rpm

8000:1E Frequency denominator

0x0001000 (4096dec)

Conversion factor in periods / m