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FAQ

FAQ

Q

What is the signal detection system of micro encoder?

A

An optical detection system is used in micro encoder mainly.
Using LED as a light source, electric signals is detected by a photo detector that detects a light passing through a rotating slit plate.
For reference, other detection systemss are magnetic (Hall element), electrostatic type, electromagnetic induction type (resolver).

Q

What is the difference between incremental and absolute type?

A

The most obvious difference is whether returning to the original point is required. 
Incremental encoder outputs signals from the point that an user start up encoder.
Absolute encoder outputs signals from the address that an user start up encoder.

This is because the internal disc slit is different.
Absolute type has the an unique slit shape that is assigned to each bit as an address.
On the other hand, incremental type has a simple slit shape and outputs a pulse according to the amount of rotation.

ディスク(回転スリット板)の開口スリット窓の配置

Incremental encoder
The output signal of the encoder has the repetition of the pulse waveform of "High" and "Low", and the pulse train is continuously generated.
Generally, This pulse train has the following combination of signals.
      Example: Single phase, 2 phase(A and B) and 3 phase(A, B, Index Z)
Since the number of pulses per rotation is determined by the size of the slit disc, the maximum resolution increases as the outer diameter increases.
Pulses generated by rotation can be added and subtracted, but an Incremental type lose the current address when the power is turned off.
To reproduce the original position, the origin (Z-phase or machine origin) is detected on the the higher level device, and then the specified count address is searched.

Output waveform of Incremental type

出力波形

Absolute encoder
An absolute encoder is classified into pure binary output, Gray code output and BCD output.
When the power is turned on, the signal of the current address is output according to the amount of rotation.

Since the number of signal lines corresponding to the resolution is required, the higher the resolution, the more signal lines. In the case of 8 bits (256 divisions), there are 8 lines (excluding power supply and GND).
In addition, there is also an output system using serial communication, which enables wire-saving and high resolution.

グレーコード出力例

グレーコード出力例
シリアル通信(SSIフォーマット)のタイミングチャート
入出力タイミングチャート.jpg

Q

Please tell me about output types of the incremental encoder.

A

Voltage output:2.2KΩ pull-up (load) resitor is built into the encoder internal output circuit. It is mainly used as a TTL input type for 5V power supplies.
電圧出力.jpg
Open collector

There is no pull-up resistor in the encoder's internal output circuit. The pull-up resistor is connected externally. The encoder cable can be extended by about 10m.


オープンコレクタ出力.jpg
Line driver:It is effective for high-speed response, noise resistance, and cable extension of several tens of meters. As a condition, the input circuit of the system for capturing signals must be a line receiver circuit.
ラインドライバ出力.jpg

Q

How can I distinguish the rotaring direction of the encoder?

A

For MTL catalog encoder, the following definition applies (if not specified otherwise):

・If the encoder shaft rotates clockwise (CW), channel A leads channel B.
・If the encodershaft rotates counter clockwise (CCW), channel B leads channel A.

正転・逆転の連続波形の方向判別例

Q

Please tell me the way to atttch a hollow-shaft encoder.

A

①エンコーダへスプリングフランジを取り付ける
 エンコーダ本体ベースのPCD取り付け用穴に、オプション品のスプリングフランジを付属品「サラネジ・ザガネA・ザガネB」を使用して取り付けます。
②段付き加工とネジ加工を施した測定対象軸にエンコーダを挿入する
 測定対象軸に段付きと先端部に雄ネジを追加工して、エンコーダの中空シャフト端面をその段付き面に突き当て差し込みます。
③ナットでエンコーダの回転軸を挟み込み固定する
 ナット締めの要領で、中空シャフトをスラスト方向で挟み込みします。
 ※ナットを締め込みする前にエンコーダシャフトを軽く回転させながら、芯振れの少ない箇所で締め込み固定してください。
④スプリングフランジと装置筐体を固定する
 最後にスプリングフランジの外周側取付穴を使用して、装置筐体と固定してください。(筐体固定用のネジは付属していません)
 また、筐体と固定する際はスプリングフランジと筐体との間には1.5~2mmほどのスペーサを利用して、スプリングフランジが筐体と接触しないようにしてください。(スプリングフランジのばね性が確保できない為)


取付方法.jpg
スプリングフランジは平板のため、ラジアル偏芯による荷重の吸収は困難です。ラジアル偏芯は約20μm以下で回転するようお願いします。
ラジアル方向の変動が大きい場合は、特殊スプリングフランジをご用意しておりますのでご利用ください。

Q

I want to display output signals of the encoder.
Please tell me the manufacturer that MTL recommend in this case.

A

When displaying incremental signals and absolute signals or importing them into PC,
the following manufacturers(domestic) have counters and boards for PC that are compatible with various encoders.


●COCORESEARCH INC.(COCORESEARCH

 COCORESEARCH INC. has a wide lineup of counters that can display the rotation angle of encoders and F / V converters that can convert speeds.

There is also an analog output option that is convenient for measurement, and Their product can be connected to many devices.

●Interface Corporation.(http://www.interface.co.jp/index.asp)for Overseas customers(Interface Amita Solutions, Inc. (interface-amita.com)
Interface Corporation. have a lineup of PCI boards for capturing encoder signals to PC, I/O output boards and counter boards.
●CONTEC CO., LTD.(Embedded Industrial Computers for Edge, IoT, & AI | CONTEC | CONTEC
エンコーダの信号を表示させるカウンタユニットや、PCへ取り込むためのボードやUSBポートから取り込めるユニットをラインナップしています。

●株式会社エム・システム技研(https://www.m-system.co.jp/Japanese/
エンコーダの信号変換器(アイソレータ)や表示カウンタをラインナップしています。上位側機器への取り込みの際に、エンコーダ信号を変換する際に便利です。

●株式会社武藤工業(https://www.mutoh.co.jp/products/~deji/index.html
エンコーダ、リニアスケール、カウンタのメーカーです。カウンタはポイント出力などの外部出力が可能で、ユーザーの設定の幅が広いことが特徴です。

Q

I am currently using an encoder made by other company, but it has been discontinued.
Can I quote an equivalent product?

A

Please tell us the manufacturer name, model, and specifications of the encoder you are using.

We will suggest from 3,000 types of our encoder lineup.

Example: E6C-NN(made by OMRON Corporation)  Click here for this equivalent product



Q

Please teach me the differance of the resolution in case multiplication circuit is installed in in incremental type.

A

・Square wave(Normal product)
The resolution is determined from the number of disc slits built-in in the encoder.
The upper limit of resolution is limited by the outer diameter of the encoder.

・Multiplication circuit
This circuit can increase the resolution of the encoder's slit disc by 2 to 100 times.
Even when installed, external four-multiplication using the phase difference of the A and B phases is possible.
Example: MEH-30-10000PST20 :Resolution 10,000P/R×20 (multiplication circuit)=200,000P/(If you use external four-multiplication, resolution is 800,000P/R)

Q

Please tell me how to convert an encoder signals on the SSI interface to parallel output.

A

⑴It is possible to convert to parallel output by using our decoder board (DECODER-*bit).
※ Supports up to 20bit (error bit not available in the case of 20bit)

⑵サンテスト株式会社製パラレル変換器を使用できます。
24bitまで接続可能で、弊社製品との動作実績がございます。
(オプションでA/B相パルス出力もあり)
詳しくはサンテスト株式会社(https://www.santest.co.jp/ja/)へお問い合わせください。
お問い合わせの際は「マイクロテック・ラボラトリーから紹介された」とお伝えいただくとスムーズです。

製品名:SSPCシリーズ https://www.santest.co.jp/ja/product/series/gy_option/sspc-02.php

Q

既設生産設備の位置表示に中空エンコーダと表示機を仕様検討していますが、下記条件で可能でしょうか。

 

 ① ボールねじにダイレクトに中空エンコーダを装着。ピッチ送りにてステージ位置検出。

              (表示0.1mm・環境的にはクリーン・精度は±2mm・測長距離2500mm)              

 

 ② 仕様頻度の多い箇所ではネジのへたり凹凸によりピッチ量とステージの位置がずれる。(機械誤差がある)

A

上記条件では、ボールねじのピッチ量=エンコーダ分解能≒測定物の位置がズレる可能性がございます。

 

解決策といたしまして、ワイヤー式リニアエンコーダMLS-50-540-4000を使用し測定物にワイヤーフックを付け測定することで、
ネジピッチに影響されることなく測定物の実際の位置を表示することができます。

 

Q

I want to extend the cable of the incremental encoder.
Please tell me the extendable length and recommended cable.

A

An extendable length and recommended cable is depending on an output type.
Please refer to the following sentence.

Voltage output and open collector output
●Extendable length:Maximum 10m
●Recommended cable:Please use a cable that has the same cross-section area and shield(or not) as the encoder cable you use.
●Note:The extension of cable may increases the rise time of the output waveform and reduces the response frequency.
               In addition to affecting the phase difference characteristics of the A and B phases, the output residual voltage increases.

・Line driver output
●Extendable length:Max 100m
●Recommended cable: Twisted pair cable (Shield cable included)
●Note:A voltage drop of about 1V occurs in case 100m.
              Please make sure that DC5V can be supplied to the encoder and use a compatible line receiver on the receiving side.
 The standard cable length of our products is mainly 1M, but 3M, 5M, and 10M patterns are available as options.
 If you would like to change the cable length, please contact us before you request a quote.

Q

What is the minimum bendable radius of the cable used for the microenco encoder?

A

The recommended value is 6 times the diameter of the cable used for the encoder.

Example:  Cable diameter used in the ME-30P series→φ4.2mm
The minimum bendable radius r=4.2×6=25.2mm

The cable diameter of each series is described in the specifications of the catalog, so please refer to it.

Q

Is possible to issue calibration certificates?

A

校正証明書、検査成績書、トレーサビリティ体系図を有償にて発行可能です。

弊社にお問い合わせいただき注文書と現品を送付ください。
発行書類のサンプルもございますので気になる方は営業部にお問い合わせください。

なお、送付いただくエンコーダにコネクタがついている場合コネクタの受け側になる検査治具を付けて送付ください。  
検査治具がない場合はケーブルをコネクタ接続部分より前で切断ください。

Q

The warranty period is 2000 hours, but what is the basis for the calculation?

A

8H (operating hours per day) x 250 days (weekdays) = 2000 hours
The service life by design is 100,000 hours due to aging deterioration of the LEDs or bearings.  

Q

Please provide the life expectancy and recommended time for replacement.

A

【Life Expectancy】 The service life by design is estimated to be 100,000 hours due to the aging of the LEDs or bearings.

【Recommended replacement period】

Please note that this is not a guideline for all products as it depends on the operating environment.

LEDの劣化(MEH60-1000Pの場合)  

23度10%劣化:5年
 
40度10%劣化:3年  

60度10%劣化:1.6年
 
23度20%劣化:20年
 
40度20%劣化:12年  

60度20%劣化:6年

Although it is affected by the operating temperature and the duration of power supply,
the light intensity will deteriorate by 10% in 3 to 5 years if the power is constantly supplied to the device.
However, if you request replacement or calibration at the above timing, you can maintain highly reliable performance.

Q

Please tell me how to buy?

A

For domestic customers:
We do not have a domestic agent, so please contact us from a trading company connected to your company.

For overseas customers:
Please contact us by inqury form first.
Then we introduce cooperating agency.

.

Q

What are MOQ and delivery date?

A

Our product is available from 1 unit.
Basically, the products are made to order, so it usually takes 2 months after receiving an order, but there are cases in which the product is in stock.
Please contact us by mail if you are in a hurry.

Q

Would you ship the product directly to the delivery address?

A

We can only accept requests within Japan.
We do not charge for shipping. (If the total amount is less than 10,000 yen, shipping charges will apply.)

Please provide us with your direct shipping address when you place your order.

Q

Are MTL's products compliant with the EU RoHS Directive (RoHS2)? Can you issue a certificate of compliance?

A

The products we manufacture and sell (rotary encoders, direct drive motors, counters, drivers, and other peripheral devices) are
EU RoHS Directive (RoHS2) compliant. (except for some models)

It can also be issued as a "Certificate of Non-Inclusion regarding Chemical Substances Covered by the RoHS Directive (10 substances)".
*It takes from one week to several months to issue the certificate, depending on the model.

Q

I would like to borrow a sample product(for domestic customer).

A

Some products are available for loan depending on the model.
The loaner product is not covered by the product warranty, since it is used to check the external dimensions, resolution, and output signal.
The loan period is limited to 3 weeks.
If you wish to borrow a product, please contact us using the inquiry form.
In addition, we do not lend sample products to overseas customers.

Q

I would like to obtain product datasheets and instruction manuals.

A

We do not upload datasheets and instruction manuals on our website.
Please contact us using the inquiry form. Our sales person will contact you.

Q

We would like to export a device using microencoders to a foreign country.
Is it possible to issue a Certificate of Non-Applicability?(for domestic buyer)

A

Possible in only japanese.
Please fill out the Certificate of Non-Applicability Request Form and fax or e-mail it to us.

Q

Can you provide local support overseas?

A

If you would like to have an investigation of your product, please send us the product itself and we will conduct the investigation and analysis.
(*We do not provide on-site support for overseas customers.)

If you plan to export our products overseas, please contact us in advance with the following information.

・Destination country
・End-user name
・Use intended application (name of equipment)

If you plan to export our products overseas, please make sure that they are fully evaluated in Japan.

Q

What kind of customization experience do you have?

A

We have a lot of customization experience, but here are just a few examples.

・Change of resolution
We can also manufacture resolutions not listed in the catalog by designing new glass or metal disks.
Please contact us with the resolution you request.

・Connector Cables
We will assemble and deliver connectors to be used in your equipment.
Please contact us to confirm whether we have the necessary equipment to assemble the connectors.

・Shaft shape change
Shaft shape change
For example, change in shaft length, shaft diameter, hollow shaft bore diameter, change to set screw type, etc.

・Full Customization
We can manufacture from scratch according to your desired specifications.

Please feel free to contact us if you have any problems such as "the encoder we are currently using has been discontinued.

Q

I would like to have a connector assy on the end of the encoder cable.

A

First, please contact us with the desired connector manufacturer and model number.

As an advantage, we can include the connector in the encoder specifications, so we can guarantee the connector part as well.
This prevents problems caused by defective connector assembly.
The connector manufacturers with which we have experience are listed below.

・日本航空電子工業株式会社(JAE) https://www.jae.com/
・多治見無線電機株式会社 https://ssl.tajimi.co.jp/
・MOLEX https://www.japanese.molex.com/molex/home
・タイコエレクトロニクス https://www.te.com/jpn-ja/home.html
・ヒロセ電機株式会社 https://www.hirose.com/corporate/ja/


We also have experience with D-Sub and MIL connectors.

Q

Can you investigate and repair encoder malfunctions?

A

For overseas users: Since we can only provide support in Japanese for cross-country repairs, we recommend that you buy a new one.

For domestic users
First of all, it would be easier if you could contact us with the following information using this form.
Depending on the contents, the product may not be damaged.

<可能な限り詳細にお伝えください>
・型式
・購入時期
・使用期間
・取付方法
・信号線の延長の有無
・不具合状況
 ・どの信号が出力しないのか。
 ・機械的な動作不良の状態

After our sales staff contacts you, please send the actual product to our company. After receiving the actual product, we will begin the investigation.

Please note that if the failure is caused by the customer's usage as a result of the investigation, the customer will be charged for the failure.

Q

What is the cause of regular noise on the encoder output waveform?

A

エンコーダ矩形波出力波形の平坦部にヒゲのようなノイズがケーブルの長さに応じて発生します。原因はケーブル内の信号線間の浮遊容量の影響でA相、B相のスイッチング立ち上がり、立下り時お互いの信号線にショックを与えて発生したものです。
したがって、A相のハイレベルの時にB相の立ち上がりのショックがA相のハイレベルの上側にノイズが現れます。同様にA相のロウレベルの時もB相の立下りで下側に向かってノイズが発生します。これを軽減するには、負荷抵抗を小さくする、ケーブルを短くする、浮遊容量の少ないケーブルにする、ケーブルのシールド線を0Vラインに接続すると、レベルを小さくする効果があります。基本的にはシステムの取り込み信号検出(H,L)の範囲外であればまったく問題ありません。 また、下図のようにA相の”H"の次はB相が”H"になってカウントUPをするため、途中でA相がばたついても、カウントUPはしないので問題ないと考えます。

Q

Can you repair a product that has been used for more than 10 years since purchase?

A

If the LEDs have been used for more than 100,000 hours, there is a high possibility that the light intensity of the LEDs will deteriorate.
We recommend the purchase of new LEDs.

Q

Can the roller of "REH-30-R series" be replaced?

A


For overseas users: Since we can only provide support in Japanese for cross-country repairs, we recommend that you buy a new one.
It is possible.
However, please send the product to us once to investigate whether there is any encoder output or mechanical abnormality.
Please send the product to us once.

We recommend that you keep a stock of these rollers as spares for repairs.
Please note that we do not sell rollers only.

Q

Is it possible to replace the wire of  "MLS series and MLA series"?

A

For overseas users: Since we can only provide support in Japanese for cross-country repairs, we recommend that you buy a new one.
It is possible.
However, please send the product to us once to investigate whether there is any encoder output or mechanical abnormality.
Please send the product to us once.

Q

When using wire type linear scales "MLS series" and "MLA series" , counting errors may occur sometimes. Is this a malfunction?

A

Depending on how the user uses the encoder, when the wire is pulled out by the control device, the encoder may not be able to track the wire when it shakes under its own weight (chattering or shocking vibration).
Make sure that the wires are as free from vibration and jump-rope-like touching as possible.

Q

While using a hollow shaft type encoder, counting errors sometimes occur. Is this a malfunction?

A

Please check the mounting condition of the encoder.
If the mounting part is slippery, the encoder may not be able to count properly.
Click here for how to mount hollow shaft type encoder.

Q

Should the ground wire (shield wire) of the encoder be connected to the device side?

A

We recommend that the shield wire of the encoder cable be dropped to flame ground to improve noise immunity.
It is also recommended that the PCB board on the customer's side be grounded as well.

However, this is not the case if there is a noise source on the FG side.

Q

The encoder signal is no longer output. What could be the cause?

A

(1)Reverse connection of Vcc and GND of power supply
  Reverse connection due to wiring error by the operator or misconnection of connectors may be the cause.

  Please have a dedicated person make the connection.


(2)Overvoltage
  Please use a regulated power supply, etc. within the range of the power supply spec.
  Also, please be careful with the wiring so as not to be affected by noise from other products.

(3)Surge noise (static electricity) application
  The following is an introduction to the static electricity countermeasures we have implemented.
   (1) Wearing antistatic work clothes
   (2) Wearing antistatic shoes
   (3) Grounded mats are installed on work tables.
   (4) Static elimination panels are installed at factory entrances and exits
   (5) Wearing antistatic wristbands
   (6)Installation of ionizers

(4)Short-circuit between signal lines
  A short-circuit between signal lines may be preventing correct reception of pulses.
  This problem is especially likely to occur when there are unnecessary or floating wires.
  Please check the end of the wiring.

CONTACT

For a quote or information about our agent, please contact us.
If you have our product, please contact us with a photo of the encoder nameplate to identify the model.
※We do not provide telephone support in languages other than Japanese.