Vibration Comparator Frequently Asked Questions

The measurement conditions (bandpass filters, etc.) for the A-band and B-band for vibration level determination are set to be the same, and the determination level is set to "UPPER" for the A-band and "LOWER" for the B-band. With this setting, if the measured value is greater than or equal to the set value, an NG (Not Good) judgment output is generated for both bands. The PLC (Programmable Logic Controller) is used to determine "UPPER," "LOWER," or "OK" based on the combination of NG outputs for the A-band and B-band.

■Measurement and Judgment Timing Chart - Example

The following is an example of specifying the measurement time using the GATE signal (AUTO) and determining whether a peakhold is being measured. The NG judgment for bands A and B​ ​is "Hi" (measured value ≥ set value).

Judgement	A-band	B-band
OVER	NG output	NG output
OK	(OK output)	NG output
LOWER	(OK output)	(OK output)

■Operating Procedure

• A reset signal is input to clear the previous measurement value and judgment result.

• Start the test device, and once it stabilizes, input the GATE signal (AUTO) and perform the measurement.

• After the measurement time has elapsed (and the GATE has been turned off), read the comparator outputs (judgment results) for bands A and B.

• The comparator results for bands A and B are imported into a PLC (programmable logic controller) and an overall judgment of "UPPER," "LOWER," or "OK" is made.

• The reset signal and GATE signal (AUTO) operate when they are at a LOW level (0V).

• The A-band and B-band comparative output is an open-collector output (DC 30V, 25mA). Negative logic is used in this example.

■Rear terminal block

The following diagram shows the rear terminal layout. Please refer to the instruction manual for signal specifications and wiring instructions, and wire correctly.

■Measurement Mode

The VC-2100 has four measurement modes: RMS, PEAK, MAX HOLD, and PEAKHOLD. When the bandpass filter frequency is set, the measurement is performed on the signal after it has passed through the bandpass filter. Measurement conditions are set separately for bands A and B. When using the "AUTO GATE" function, the measurement mode will be set to either "MAX HOLD" or "PEAKHOLD". For details on each mode, please refer to ​"VC-2100 Measurement Modes and Comparison Function".

■Settings and Operation

We will conduct test tests to determine the measurement conditions. Please refer to this simple operation manual for instructions on how to set up the VC2-100.