Engineering Notes by Oriental Motor

Monitor Your Machine Like a Traffic Light System

[fa icon="calendar"] Jun 19, 2020 8:00:00 PM / by Johann Tang

Johann Tang

For automated factories, motor failures mean lost production and lost revenue.  Being able to identify the specific issue in advance and its location is critical to maintaining production efficiency.  To be successful, extra sensors must be added to detect abnormalities.  There may be an easier way.

Challenge Monitor Your Machine Like a Traffic Light System


Using motor systems with status monitoring capabilities is one way to make lives easier for everyone involved.  Being able to monitor various statuses of a system is the basis of predictive maintenance, which can identify potential issues before they become actual problems.

Application Example

In this example, a motor is assembled with a rack and pinion mechanism and lifts the load up and lowers it down.  Imagine a factory with tens or even hundreds of these.  Being able to detect potential issues is critical to maintaining the highest production efficiency.

How would predictive maintenance work?

  • Collect specific information.
  • Communicate the information.
  • Take action before failure occurs.
Rack and pinion lift system

First, we need to decide what we want to monitor from the motor.  Besides excessive load, heat is a motor's #1 public enemy.  A motor's life is rated by its bearing grease life, and the bearing grease life is rated based on operating temperature.   For this example, we will focus on most important variable that affects motor life - motor temperature.

Another decision we need to make is whether or not we need communication capabilities from the motor driver.  Basically, we need to find out how to acquire that information.  Is it acquired through data transmission through an industrial network, an analog output, or digital I/O?

TIP: Benefits of Networking
  • Simple Wiring

A good way to minimize time-consuming I/O wiring is to connect using an industrial communication network, such as EtherNet/IP or EtherCAT.  The number of wires that need to be connected between the master / host controller and the motor driver are significantly reduced.

  • More Remote I/O

Since a driver is limited by the number of its physical I/O, more "remote" I/O can be accessed by setting up an industrial network with the motor driver.  This means more variables can be monitored.

Examples of other status outputs that can be monitored:

  • Driver I/O status
  • Motor Position error
  • Driver temperature
  • Overvoltage
  • Undervoltage
  • Overload time
  • Overspeed
  • Cumulative load
  • Tripmeter, odometer
  • RS-485 communication, homing and other errors

After you decide which variables you want to monitor, find the specific outputs that can output this data, then connect them to your PLC, PAC, HMI, or whatever you're using as a monitoring system.  Once connected, the status information can be continuously communicated to the master via I/O or industrial network.  The settings for the programmable output can be set up with a different threshold to fit various needs.  

In the following image, we show how these "information" outputs work.  

 

In this example, The INFO-MTRTMP output is set up to trigger ON if the motor's operating temperature exceeds 70° C.  The ALM-A output is set up to trigger ON if the motor's operating temperature exceeds 85° C.  The difference, besides the obvious temperature thresholds, is that when the ALM-A output triggers, the motor will also stop operating.  

TIP: What is the Difference Between a Standard Output and an Information Output?

This is only specific to Oriental Motor's products.  A standard output is a default, physical output that is assigned at the factory.  An information output is a optional output that can only be accessed through an industrial network or with the MEXE02 software status monitor function.

The INFO outputs are designed to provide warnings before the alarm generates and stops the motor.

Now, how are we going to show this information to the operator?

To show the concept, we will show the status with a traffic light system.  It is the easiest concept to use in our application example.

  • GREEN - everything is OK and the motor is operating normally.
  • YELLOW - INFO-MTRTEMP output triggered ON indicating that temperature is above 70° C.
  • RED - ALM-A output triggered ON indicating that temperature is above 85° C.

Of course, a traffic light system may not work well in a real life scenario.  For any kind of communication, you want the user to understand quickly so action can be taken quickly.  How the information is displayed is up to the operator or programmer.   

Here's another status monitor example.  This time, we're using our dedicated MEXE02 software to monitor these information outputs.  This function can be accessed with the "Information Monitor".  Of course, this software was designed to monitor one motor at a time.  An operator's interface at a factory will contain specific IDs to identify which motor axis is at fault.

FYI when communication is established between the software and the driver, some boxes should be colored and some boxes will stay blank.  Make sure to click the check box to start monitoring.

Most importantly, to make all this happen in the best way, a driver with industrial communication capabilities may be necessary.  These drivers offer communication ports and can provide a lot more data than a driver without communication.  It really depends on what you want to monitor. 

Oriental Motor offers dedicated EtherNet/IP or EtherCAT compatible drivers for AZ Series equipped  stepper motors, rotary actuators, and linear motion systems.

Solution AZ Series Network Type Drivers

Single-Axis Single-Axis Multi-Axis
EtherNet/IP compatible EtherCAT EtherCAT
AZ Series EtherNet/IP drivers AZ Series EtherCAT drivers AZ Series Multi-axis EtherCAT driver
EtherNet/IP Driver EtherCAT Driver Multi-Axis Driver

Here's a video tutorial that shows how to use an AOI to monitor motor status on the Studio 5000 Logix Designer software from Rockwell Automation (for Allen Bradley PLC users).

OM How-To Video: using AOI to monitor motor status

Watch More Videos

 

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Related post: Preventive vs Predictive Maintenance: Which is More Efficient?

 

Topics: Stepper Motors, Alphastep Hybrid Control, Linear & Rotary Actuators, VIDEOS, Network, Application Examples, Troubleshooting

Johann Tang

Written by Johann Tang

Johann Tang is a Product Specialist at Oriental Motor USA Corp. with over 15 years of knowledge and experience supporting applications of various types of electric motors, gearheads, actuators, drivers, and controllers.