Tachometer Frequently Asked Questions

The TM-3100 series is compatible with the older TM-800/TM-8000 and TM-2100 series. As before, four basic sets are available: TM-3110 (display only), TM-3120 (BCD open collector output), TM-3130 (analog output), and TM-3140 (comparative output).

However, to ensure compatibility with the TM-2120 (model with BCD output), you will need to switch to the TM-0321 BCD output card (voltage output) (resulting in a TM-3110 + TM-0321 combination).

The output current of the BCD output of the TM-800/8000 series and TM-2100 was 4 mA, but the voltage output of the TM-0321 is an open collector output circuit that is internally pulled up to +5 V with a 10 kΩ resistor.
Please pay attention to the impedance of the receiving circuit and the connections when using a receiving circuit that supplies current.

【supplementary explanation】

In addition to the existing functions, the TM-3100 series adds "SS measurement" and the optional "TS-0350 (RS232C/GATE)" as new features.
The basic concepts of the TM-3100 series are as follows:

• The input signal's "frequency" is measured, and that value is then converted to the units of each measurement item and displayed.

• There are two measurement methods: "NORMAL (normal continuous measurement)" and "SS (start-stop average measurement)".

• Simply set the units for the "measurement items," and the system will automatically convert and display the units.

This section provides an overview of the measurement methods and measurement items. For information on the calculation functions and gate-based measurements of the TM-0350 (RS232C/GATE), please refer to the instruction manual.

Measurement method (MEAS MODE)

1-1 NORMAL
For example, it repeatedly measures and displays the updated data according to the set data update time of "1 second". NORMAL mode performs general rotation speed and line speed measurements and is compatible with older models such as the TM-800, 8000 series, and TM-2100 series because it uses the same measurement method.

1-2 SS (START/STOP)
This function measures the average, maximum, and minimum values within a given measurement interval. There are two measurement modes: manual and automatic, depending on the start and stop conditions of the measurement interval. In manual mode, the measurement interval is set using the START/STOP buttons (or the external input on the TM-0350). In automatic mode, the start conditions and measurement time are set.

■SS-MANUAL
Select “MANUAL” in [SS MEASUREMODE]. In MANUAL measurement mode, the average value and other parameters are measured over the period from when the START button is pressed until when the STOP button is pressed.

■SS-AUTO (Auto)
Select "AUTO" in [SS MEASUREMODE]. In AUTO measurement mode, pressing the START button puts the device into a ready state. Measurement begins when the set start condition is met, and the average value, etc., is measured within the measurement time interval set by the stop condition.
For example, with the settings "START: 2000 r/min, STOP: 10 s", press the START button at 1000 r/min, gradually increase the rotation speed until it reaches 2000 r/min, then start measuring. AVERAGE, MAX, and MIN will be measured over the following 10 seconds. Alternatively, for example, press the START button at 2500 r/min, decrease the rotation speed until it reaches 2000 r/min, then start measuring. Pay attention to the rotation speed when pressing the START button.

■Main screen and sub-screen

When you select [DISPLAY] → [2 LINES] in the settings mode, the main screen will display the NORMAL measurement values, and the sub-screen will display the SS measurement values AVERAGE (average), MAX (maximum value), and MIN (minimum value) that you have selected. The figure below shows an example of the main screen and the screen set for main and sub-display.

Measurement items

The TM-3100 series measures the period (frequency) of the input signal. Using this measured frequency, it performs calculations with the value set for the measurement item as a coefficient, and displays the result in the specified unit.
The measurement items and calculation formulas are shown in the following table.

Hz、kHz

*Example of FACTOR usage: For example, if you have a gearbox and the detector is mounted on the input shaft, and the rotational speed you want to display is on the output shaft, set the reduction ratio in FACTOR. Normally, FACTOR is used with a setting of "1".

2-1 Settings Mode (MEASURE)
In the "MEASURE" setting mode, you configure the "measurement method," its associated "measurement items," and "measurement units." Whether you select NORMAL (normal continuous measurement) or SS (start-stop average measurement) as the measurement method, the settings for measurement items and units will be the same. Generally, NORMAL (continuous measurement) is used. The following diagram illustrates the flow of setting in the "MEASURE" setting mode.

2-2 Setting Mode (FUNCTION)
In the "FUNCTION" setting mode, you can configure the display content related to the measurement method ("NORMAL" and "SS") and set the start and stop conditions for SS measurement. In the "NORMAL" setting, continuous measurement is performed with automatic updates, so there are no start and stop conditions to set. The following diagram shows the flow of setting in the "FUNCTION" setting mode.