FV Converter FV series FAQ

When inputting a pulse signal (negative voltage) centered around 0 V, recommend you to set the input signal type to AC.

• SIGNAL: Input singal type

 



 

• Press the MENU button to start the setting mode. Then, expand 0: INPUT > INPUT-SIGNAL to show the input signal condition setting item.

 

In the setting mode, set the input signal format to PULL UP.

Operation procedure
1. In the measurement mode, press and hold [MENU] key to move to the setting mode.
2. With [∧]/[∨] key, select [MENU　0：INPUT] and press [SET/NEXT].
3. With [∧]/[∨]key, select [INPUT-SIGNAL　3：PULL　UP] and press [SET/NEXT].
4. By pressing [MENU] key, you will go back to the measurement mode.

The response of output signal of the FV-1500 is one cycle +3.5µs of the input frequency.

When the input frequency range is 0.2 Hz to 320 kHz and input signal is 0.2 Hz, the output update time is approx. 5 seconds.
When there is no input signal, voltage value and current value of the output signal are held. If you do not set the stop time of the FV-1500, the output signal will become 0V after 5.5 seconds. (It becomes 0 mA or 4 mA when current is outputted.)

1. Is it possible to reset the FV-1500 to the factory default settings? (settings at the time of factory shipment)
   Hold [Menu] + [SET/NEXT] and power ON
   [MEMORY ALL CLR? ] → [Y : SET/NEXT N : MENU]
   Select "SET/NEXT" to start reset
   
   
2. Reset of 10 setup conditions (Calibration values will not be cleared.)

Hold [<] + [SET/NEXT] and power ON
[ PANEL COND ALL CLR?] → [Y : SET/NEXT N : MENU]
Select [SET/NEXT] to start reset.



*Condition: This term is used to refer to "setup condition" in exclusive instruction manual. There are 10 memories to be used. Memory which is not "a condition" means each setting values.

If an input signal suddenly stops, the FV-1400 outputs at 0V from 1 second after the input signal stops. (Except when the moving average function is in use.)

The output voltage depends on the interval (period) of the input signal. If the input signal suddenly stops, the FV-1400 waits the signal to come for 1 second. However, when there is no input signal for more than 1 second, the output voltage becomes automatically 0V.

When you connect the input signal and output signal of the FV-1400 to the AD conversion board of a PC, noises from the sample clock of the AD conversion board may be mixed with these signals. Following diagrams are examples of the noise waveforms of the input signal and the output voltage signal.

Noise waveforms of the analog signals of the FV-1400

Even though you connect only the output signal from the FV-1400 to the AD conversion board, the noises due to the sample clock may be mixed with the output voltage signal, and moreover may travel to the input signal. In case of setting the input coupling of the FV-1400 to "AC coupling", an accurate measurement may not be performed due to the malfunction caused by the noises mixed with the input signal.

Please try these countermeasures as follows. In above example cases, the problem was solved by doing both of (1) and (2).

• (1) If possible, the signal from the sensor should be inputted through an amplifier; that is, use "rectangular wave signal" such as the output signal of the MP-981 Rotation Detector. Moreover, set the input coupling of the FV-1400 to "DC coupling".

• (2) Adjust the trigger level of the FV-1400 in order not to pick up the noises.

• (3) Inquire the noise countermeasure from the manufacturer of the AD conversion board.

• (4) Add a filter circuit (an isolation amplifier, etc.) and transmit the output voltage signal or the input signal of the FV-1400 through it, which prevents the noises due to the sample clock from traveling to the input signal. The filter circuit is to be supplied by our customers.

The settings and the meanings of input range, output range, factor, and monitor display are as follows.

The following formula can be established.

（1）

The factor can be obtained from the following formula.

（2）

The following diagram shows the relationship between input frequency and output voltage.

Example 1: Setting the input range in the unit of revolution speed <r/min>.

1. How to use formula (1)

Factor

Obtain the factor from formula (1). The display units will be r (1 revolution) and min (minute) based on the measuring unit r/min. Based on the settings of pulse count per 1r=360 and number of seconds for display unit: 1 min=60s, the following formula is established.

Monitor display

Based on the setting of factor=6, the monitor display value is displayed in the unit of r/min automatically. 3-digit value is displayed. Use the information as a simple monitor.

Input range

Although the maximum measuring revolution is 5000 based on the condition, set 5.00k (k=factor of 1000) since the value comprises 3 digits. When a signal exceeding this setting value is input, Input Over occurs. In this case, it is necessary to review the condition such as increase of the input range setting value. A limit is set for the input range setting and when the setting exceeds the limit, an error message is displayed.
Refer to "5.1 Input range" of the Instruction Manual for the details.

Output range

Set a maximum output voltage for the output range. This function limits the maximum output voltage up to 1 V when a device of the connection destination such as a recorder applies 1 V input. Refer to the "Setting value" column of the table provided above for the summary of the values that are obtained.

2. How to use formula (2)

Based on maximum revolution for measurement=5000 r/min and pulse count of the rotary encoder= 360 P/R:

Based on the measurement condition, input range=5000 and as a result of conversion of formula (3), the factor is:

The output range is the same as for item 1.

Example 2: Set an input range with frequency <Hz>

Obtain the maximum frequency using the method 2 in Example 1. Based on the maximum revolution 5000 r/min;

Since the input range is set to the maximum frequency 30000, the factor is;

Based on the measurement condition of 5 V, set the output range to 50%.
Refer to the "Setting value" column in the table shown above for the values that were obtained.

Example 3: Set an input range in speed (m/min).

Based on the specification of PR-721 in the measuring unit m/min;

Based on the maximum speed for measurement 100 m/min, set the input range to 100. When a signal exceeding this setting value is input, Input Over occurs. In this case, the setting needs to be reviewed.

Since the output voltage is 10 V based on the output condition, set 100%. Refer to the "Setting value" column of the table indicated above for the values that were obtained.

The standard specification of the FV-1100 Converter is maximum 10 kHz.

When the operating frequency is less than a half of the frequency range, the output voltage grows smaller and the ripple becomes larger. In above situation, the accuracy of the operating range becomes poor. We recommend you to modify the frequently used frequency range close to the full scale frequency.

(Example)

The accuracy for 10 kHz range: ± 0.2 % → 20 mV/ 10 V full scale/ 10 kHz full scale

 

When the operating range is 1 kHz or less: 1 kHz = 1 V, the accuracy for 1 kHz → 20 mV ÷ 1 V= 2 %/ 1 V/ 1 kHz

 

When change 1 kHz into full scale → 0.2 %/ 10 V full scale/ 1 kHz Full scale