FV Converter Frequently Asked Questions

The meanings and relationships between the input range, output range, factor, and monitor display settings are as follows:

 

Input Range	Set the maximum value to measure (the maximum value displayed on the monitor). For example, you can set the maximum measurement value, such as 500 r/min or 100 m/min.
Output range	Set the maximum values for output voltage and output current in percentages. Voltage: 0 to 10V / 0 to 100% Current output (optional): 0 to 16 mA / 0 to 100% or 4 mA to 20 mA / 0 to 100%
factor	This is a unit conversion coefficient. It is used when converting frequency to rotational speed (r/min) or velocity (m/min).
Monitor display	The value displayed is the input signal frequency divided by a factor and converted.

 

Furthermore, the following relationship holds true:

（1）

 

The factor can also be calculated using the following formula.

（2）

 

The relationship between input frequency and output voltage is shown in the following diagram.

 

Example 1: Set the input range in units of rotational speed <r/min>.

 

Measurement conditions	Set value
RP Series Rotary Encoder: 360 P/R Maximum measured rotational speed: 5000 r/min Output voltage: 0 to 1 V / 0 to 5000 r/min Set the input range to rotational speed in r/min.	Input range: 5.00 kHz Factor: 6 Output range: 10% Measurement range: Monitor display 0 to 5.00 k

 

 

1. Method using formula (1)

factor

 

The factor is calculated from equation (1). Since the measurement unit is r/min, the display units are r (1 revolution) and min (minute). Also, the number of pulses per 1r = 360, and the display unit is 1 min = 60 s;

 

 

Monitor display

Setting the factor to 6 will automatically display the value in r/min using the following formula. The display will show 3 digits. Please use this as a simple monitor.

 

 

Input Range

The maximum rotational speed to be measured is 5000 according to the conditions, but since the setting is in three digits, we set it to 5.00k (k = 1000 times). If a signal exceeding this setting is input, it will result in an input overload. In this case, it is necessary to review the settings, such as increasing the input range setting. There is a limit to the input range setting, and an error will be displayed if the setting exceeds this limit. For details, please refer to the instruction manual, "5.1 About Input Range".

 

Output range

The output range sets the maximum output voltage. If the connected device, such as a recorder, has a 1V input, this function also limits the maximum output voltage to prevent it from exceeding 1V. The measurement condition is 1V, so set it to 10% of the input. The obtained values are summarized in the "Setting Value" column of the table above; please refer to it.

 

 

2. Method using equation (2)

Based on a maximum measured rotational speed of 5000 r/min and a rotary encoder pulse count of 360 P/R;

 

Based on the measurement conditions, the input range is 5000, and transforming equation (3), the factor is:

 

 

This is the result. The output range is the same as in section 1.

 

Example 2: Set the input range by frequency <Hz>

Measurement conditions	Set value
RP Series Rotary Encoder: 360 P/R Maximum measured rotational speed: 5000 r/min Output voltage: 0 to 5 V / 0 to 5000 r/min Set the input range in frequency units (Hz).	Input range: 30.0 kHz (30,000) Factor: 1 Output range: 50% Measurement range: Monitor display 0 to 30.0 k

 

 

• Input Range

We will determine the maximum frequency using method 2 in Example 1. Since the maximum rotational speed is 5000 r/min;

 

• factor

Since the input range is set to a maximum frequency of 30000, the factor is:

• Output range

Based on the measurement condition of 5V, the output range is set to 50%.

The values obtained are summarized in the "Settings" column of the table above; please refer to it.

 

Example 3: Set the input range to speed <m/min>

Measurement conditions	Set value
RP-721 Roller Encoder: 120 P/R Roller diameter: πD = 0.2 m Maximum measurement speed: 100 m/min Output voltage: 0 to 10 V / 0 to 100 m/min Set the input range to speed in m/min.	Input range: 100 Factor: 10 Output range: 100% Measurement range: Monitor display 0 to 100 m/min

 

 

• factor

From the RP-721 specifications, the unit of measurement is m/min;

• Input Range

Since the maximum speed you want to measure is 100 m/min, set the input range to 100. If a signal exceeding this setting is input, it will result in an input overload, and you will need to review the settings.

• Output range

Based on the output conditions, the output voltage is 10 V, so we set it to 100%. The calculated value is summarized in the "Setting Value" column of the table above; please refer to it.