Siemens Sinamics CU320 Modules: Beyond the User Manual

About Sinamics S120 CU320 Modules

There are two Sinamics S120 CU320 Modules. There is the CU320-2 DP, which is the 6SL3040-1MA00-0AA0, and the CU320-2 PN, which is the 6SL3040-1MA01-0AA0.

These multi-drive Control Units increase axis count and functionality. They have an Ethernet port, as well as more I/O and controller to controller communication. Each unit can manage up to 6 servo or vector axes in a high performance system. For standard systems, up to 12 V/Hz axes can be controlled from one CU320-2 unit. These Control Units significantly reduce system costs, as they increase functionality for positioning, safety integration, and drive control allowing all these functions to be controlled by one unit versus several.

Siemens CU320 control units also provide additional flexibility with a high number of programming options and digital inputs. With up to 12 binary inputs, the modules’ high I/O count add ease of use. The additional Ethernet port expands programming options as well. Overall, the CU320-2 control units allow for simple yet flexible performance with minimal cost and space requirements.

If you want to learn more about these high-performance drives, check out our blog on Sinamics s120 fault codes.

CU320-2 DP Module

CU320-2 DP

The CU320-2 DP is a Sinamics Control Unit with a Profibus interface. It is a central Control Module in which the closed-loop and open-loop functions are implemented for one or more Line Modules and/or Motor Modules. It can be used with firmware version 4.3 or greater. It has 12 digital inputs, 8 digital inputs/outputs, 4 DRIVE-CLiQ interfaces, a Profibus and Ethernet interface, a serial interface (RS232), an option slot, and 3 measuring sockets.

MRO Electric stocks new and refurbished CU320-2 DP Control Units, which is part number 6SL3040-1MA00-0AA0. If you would like a replacement module, please call 800-691-8511 or email


CU320-2 PN Module

CU320-2 PN

The CU320-2 PN is a Sinamics S120 Control Unit without a Profibus interface. It has the same interfaces as described above, however without the Profibus port. It is also a central control unit with closed-loop and open-loop functions that can be implemented for one or more Line or Motor modules.

MRO Electric stocks new and refurbished CU320-2 PN Control Units, which is part number 6SL3040-1MA01-0AA0. If you would like a replacement module, please call 800-691-8511 or email

Determining Encoder Selection

What is the role of the encoder?

For any motion control process to work, a sensing device is needed to provide reliable feedback sensing. The encoder is the part of the machinery that furnishes feedback information. How does the encoder work? The encoder receives a motion signal and converts this signal into an electrical signal that can be read by some sort of motion control system, like a PLC. The motion control system then uses the signal to control conditions such as speed, direction, and position on your machinery.  This process is consistent in any application: The exchange of information between the machine and the controller through the encoder signaling generates the exact performance function.

“The core function of the encoder is to provide information about the motion of the moving parts in your system.”

Adam Gross, Lead Technician, MRO Electric

Selection requirements

What do you need to know when choosing an encoder that is right for your application? There are a couple of fundamental points when selecting which encoder is correct for the job. 

When selecting an encoder, one thing you will need to determine is the application control specifications. Applications can range from very simple machine applications to complicated machinery. Some applications are simple and require simple position or speed control with a low degree of accuracy needed, while more sophisticated machinery may need a higher level of feedback. Knowing the application of the encoder is vital in the selection process.

Another thing to consider is the encoder properties. Typically, this involves the number of rectangular pulses per motor revolution. A pulse number is delivered by two channels. The two channels have a phase shift of one-quarter of a pulse length, sometimes referred to as quadcounts. In this way, motor rotation direction can be detected using the four distinct states per single pulse. These four pulses represent the real resolution. For instance, if an encoder has 2,000 counts per pulse term; it gives 8,000 states per turn, which determines a nominal resolution of 360/8000=0.045°. Encoders detect motion encompassing a wide range of counts per turn. That means you must decide whether your application requires a simple encoder with fewer CPT or a more complex encoder that can detect an extremely accurate position or speed. 

Other factors can impact resolution. The mechanical layout is a consideration for encoder resolution as well as other influences like analog or digital signals. Underlying physical foundations like optical, magnetic, or inductive principles can also play a part in encoder resolution. 

Exposure to specific environmental elements factors into selection consideration as well. The encoder may require a shield if it is in an environment where it is likely to be exposed to conditions such as dust, moisture, or corrosive chemicals. Encoders are susceptible to environmental extremes such as temperature, shock, or vibration.

Encoder Types

A simple approach to guide your determination in encoder options is to characterize the type of movement the encoder is monitoring. There are three commonly used encoders: Linear, rotary, and angle encoders.

 The linear encoder is an encoder that senses the movement of linear objects to encode position.  A scale is determined that allows the sensor to convert the encoded position into a signal that could be analog or digital. The signal can then be decoded into a position by a motion control system. Machining tools use the linear encoder to coordinate measuring machines, such as a cut length application. In cut-length applications, the control device and encoder determine how much of a particular item, such as cloth material, is fed through the machinery, measuring where to cut. Sometimes a cable is run between an encoder and a moving object, using a transducer to produce an analog or digital output signal to establish the movement or position of the object.

For rotating objects, a rotary encoder is used. Providing feedback about the movement of a rotating object or device, a rotary encoder converts the angular position of the moving shaft into an analog or digital output signal. This signal is used to allow a control system to determine the position or speed of the shaft. Rotary encoders can be mounted directly to a motor or any machinery with a rotating shaft and are sometimes called shaft encoders. The two main types of rotary encoders are the absolute encoder and the incremental encoder.  What is the difference between the two? The difference is in the output.

The absolute encoder indicates the current shaft position, while the incremental encoder provides information about the motion of the shaft. The Absolute encoder is an angle transducer, whereas the incremental encoder typically processes information such as speed, position, and distance. Applications for the rotary encoder involve such things as robotics and industrial controls, which require monitoring and/or control.

Angle encoders are like rotary encoders; however, they are more apt to offer higher accuracy. It measures the angular position of a rotating shaft. A disc-shaped rotator uses an optical grating that operates with an optoelectric sensor on the stator. Because optical technology is dependent on the tightly constrained rotation of the rotor in relation to a stator, an angle encoder is used to keep the two parts concentric using bearings.

Encoders have the potential to elevate performance and increase productivity through their sensing technology. Selection consideration includes many aspects, some of which are presented above. For a closer look at the encoders offered at MRO Electric, please visit our website, or give us a call.

Product Spotlight: Square D EDB34030 Circuit Breaker

The Square D EDB34030 is a three pole, 30 Ampere circuit breaker. At 277V, this miniature breaker is reliable, sustainable, efficient and safe.

Part Number: EDB34030
Item Weight: 3.6lbs
Product Dimensions: 9.7 x 6.1 x 4.5 inches
Voltage: 480V
Amperage: 30A
Trip Rating; 875A
Mounting Mode: Bolt-on
Interruption Rating: 18kA

Square D EDB breakers by Schneider Electric are available in a range of amperages varying from 20A to 60A. This particular model, the EBD34030, is 30A.
This breaker is set apart from other breakers because of its compact size at 9.7 x 6.1 x 4.5 inches, while the typical breaker is around 8 x 8 x 12 inches. As a bolt on mount, it is preferred in commercial and industrial applications where vibrations might be considered an issue. When installing, be sure to use the recommended #12-#6 AWG AI or #14-#6 AWG Cu Lug wire. This breaker is ideal for NF series panel-boards to offer superior overload and short circuit stability by utilizing thermal magnetic protection. It is also HACR rated, UL listed and CSA certified.

MRO Electric and Supply stocks Square D circuit breakers, including the EDB34030. For more information or to request a quote, please contact us at 800-691-8511 or at

Kawasaki E3/E7/E9 Controllers

Being a leader of the robotics industry for over 50 years, Kawasaki has developed one of the most complete lines of e-controllers on the market. All of these controllers are suited with a wide array of features including:

  • High powered CPU performence
  • Large, easy to use LCD Display
  • Optimized key layout
  • Easily accessible safety switches

The E76/77 family of controllers are very compact and used for smaller robot arms. One of these arms are the RS003N Robot, which has a maximum payload of 3kg and has horizontal and vertical reaches of 620mm and 967mm, respectively. The controllers with these robots specialize in assembly and material handling applications.

The E9 family of robotic teach pedants are also built very compact, however these devices are typically used in medium-duty applications. Unlike the other two families of controllers, the E9 family features an open structure system with a direct cooling system. However, like the E7 and E3 families, the enclosed structure with indirect cooling is an available option. The E9 family takes full advantage of the digital servo drive powering it to have a maximum payload capacity of 40kg.

E30/32/33/34 controllers at their base are very alike the E76/77 controllers but with more power. These devices are not as compact as the previous devices we have discussed, however the reason being they are highly expandable and are easier to maintain. Features such as Kawasaki’s K-Logic sequencer software allow the addition of up to 16 total controllable axes. The E3 family of Kawasaki e-controllers are able to handle the following maximum payloads:

  • E30 – 145 kg
  • E32 – 180 kg
  • E33 – 195 kg
  • E34 – 180 kg

If you are interested in learning how to purchase the robot arm, the controller, or any other part/device that goes into an industrial robotic set-up, please call MRO Electric and Supply at (800)691-8511 or email us at and we will help you get what you need.


ABB Robotics 3HAC028357-001 Teach Pendant

The 3HAC028357-001 is a modern ABB Robotics Teach Pendant designed to be used with the IRC5 Industrial Robot Control, one of the most popular robotics controls on the market. Also known as the “FlexPendant”, the 3HAC028357-001 is characterized by its clean, color touch screen-based design and 3D joystick for intuitive interaction.

The 3HAC028357-001 TPU (or teach pendant unit) is a hand held operator unit used to perform many of the tasks involved when operating a robot system: running programs, jogging the manipulator, modifying robot programs and so on.

The FlexPendant is designed for continuous operation in harsh industrial environment. Its touch screen is easy to clean and resistant to water, oil and accidental welding splashes.

ABB FlexPendant

The 3HAC028357-001 replaces the legacy 3HAC023195-001 teach pendant.

The standard cost for a new ABB 3HAC028357-001 direct from the manufacturer or authorized distributor is typically in the $6000-7,000 range. MRO Electric is able to supply these pendants at a much lower price point, and we warranty all of our robotics parts for 12 months.

If you would like a free quote on a replacement ABB 3HAC028357-001, please email us at or call 800-691-8511.

Siemens Sinamics DME20 Hub Module: Beyond the User Manual

The Siemens SINAMICS DME20 DRIVE-CLiQ Hub Module is used to implement a star-shaped topology of a DRIVE‑CLiQ line. Two DME20 DRIVE‑CLiQ Hub Modules can be connected in series. Signals from more than one encoder can be collected with one DRIVE-CLiQ Hub Module and forwarded to the Control Unit through a single DRIVE-CLiQ cable. The Siemens SINAMICS DME20 is used to connect direct measuring systems for the feed axes and expansion axes of the S120 Combi.


The DME20(6SL3055-0AA00-6AB0) DRIVE-CLiQ hub module offers the following features:

  • 6 DRIVE-CLiQ sockets for connecting up to 5 more DRIVE-CLiQ modules
  • 1 connection for the power supply module via 24V DC circular supply connector
  • 4 x 0.75 mm pins (pins 1 and 2 are bridged, along with pins 3 and 4)

The SINAMICS DME20 uses the Siemens STARTER software to parameterize and commision drive units. The STARTER commissioning tool can be used for commissioning, testing through a control panel, drive optimization, diagnosing drives, and setting up and running built in safety functions. The tool offers support for various operating wizards, running trace functions to optimize drive controllers, creating and copying data records, loading projects from the programming device to the target device(and vice-versa), along with so much more.

Does your Siemens SINAMICS DME20 hub module need to be serviced? As with all of our services, our repairs come with a 12 month guarantee. Our repair service is based on doing the right job, and getting your part back to you as soon as possible. Every part we refurbish is tested to make sure they work the way they are supposed to. Our factory-trained technicians have many years working with Siemens products. Minimize your future downtime today by contacting MRO Electric and Supply right now.

For a free repair quote on DME20 hub modules, please email or call 800-691-8511.  For more information on our Siemens repair capabilities, you can visit our Siemens Repair page.

Siemens Sinamics GM150: Beyond the User Manual

The SINAMICS GM150 is a universal single-motor drive for applications involving square-law and constant load characteristics without regenerative feedback into the line supply. These drives are especially suited for pumps, fans, compressors, mixers, crushers and ships. Simplicity of the Siemens SINAMICS GM150 variable speed drives is due to the use of standardized engineering tools such as SIZER and STARTER. Some of the advantages of the GM150 include:

  • Power ratings from 9 MW to 27 MW
  • Induction and synchronous motors
  • Integrated maintenance functions
  • Factory-tested interaction between motor and drive
  • Simple integration into existing automated system
  • Compact design with highly flexible configuration
  • Top tier toughness due to HV-IGBT/IGCT technology with a fuseless design
  • Designed to handle both air and water cooling


The drive units are equipped with maintenance functions that tries to prevent faults by fixing them before they happen. The drive will send signals when it knows that a part will need to be fixed or replaced. With a high degree of flexibility when it comes to connections and mounting, Siemens GM150 and SM150 systems have very user friendly operator panels for the easiest operator control and visualization. Reliability is key in any automated system.

Does your Siemens SINAMICS GM150 module need to be serviced? As with all of our services, our repairs come with a 12 month guarantee. Our repair service is based on doing the right job, and getting your part back to you as soon as possible. Every part we refurbish is tested to make sure they work the way they are supposed to. Our factory-trained technicians have many years working with Siemens products. Minimize your future downtime today by contacting MRO Electric and Supply right now.

For a free repair quote on GM150 modules, please email or call 800-691-8511.  For more information on our Siemens repair capabilities, you can visit our Siemens Repair page.