...in sensors (by Uwe Koppe, MicroControl):

When we take a look at today’s sensor market for temperature and pressure, we recognize that the vast majority of sensors is equipped with an analog interface or a quite simple digital one. This is caused by the fact that the market requires cost-effective, small and robust devices. However, customers demand more than just a converted physical value: they need sophisticated diagnosis facilities, digital calibrated sensors and high accuracy in order to compete in our globalized markets. They do not want these new features to increase the price of a sensor. This challenging situation is a welcome playground for CANopen with its sophisticated communication methods and large resources of device profiles. The device profile for “Sensors and measuring devices” (CiA DS 404) has been available for several years. It was designed to fulfill the requirements of a modern sensor application - the feedback of the market is positive.

Taking a look into the future, I expect that CANopen will be a standard for many sensor applications, replacing today’s analog interfaces. Due to the large variety of micro-controllers with CAN, the costs for smart CANopen sensors can compete with the old fashioned analog interface.
Congratulations for the 10th anniversary of CANopen! It does not make the world a better one, but it makes it a smarter one.

...in motion control (by David Greensmith, Baldor):

Baldor have experienced great success with CAN based systems. Our first proprietary protocol actually preceded the formation of CANopen. Later developments such as our motion controllers and intelligent servo drives, quickly took advantage of CANopen support as standard.
Advanced CANopen device interfacing is simple, with intuitive and powerful CAN keywords within our high level language providing access to digital and analog I/O expansion, software events allow for immediate response to specific bus events or data exchange and generic keywords provide for object dictionary, PDO and SDO data access. As a result CANopen communication has had a significant impact on Baldor’s product success and will continue to do so. Not only is CANopen a cost effective network on a per node basis, it offers many other benefits.

There are over 440 vendors, widely available silicon, probably best documented and supported product profile definitions of any network technology, a simple low cost physical layer and a vast established experience base in the marketplace.

Our enthusiasm for CANopen and its future use, lays firmly in its partnership with real-time Ethernet, specifically Ethernet Powerlink (EPL). The adoption of CANopen profiles by the Ethernet Powerlink Standardisation Group (EPSG) in agreement with CiA, further strengthens this point by providing the grounding for seamless connection to CANopen networks via integrated Ethernet to CANopen gateways.

Our drives will operate as CiA DSP 402 positioning drives, either via CANopen or EPL. When controlled via EPL they can also act as CiA DS 301 managers, controlling their own subnet of CANopen devices, such as I/O, making for a very convenient system architecture for expansion or interfacing to CANopen devices.

Designers will benefit from a real-time synchronous ‘backbone’ for time critical control (EPL) with all the benefits of CANopen expansion in other areas. Likewise CANopen users looking for state of the art CiA DSP 402 positioning drives will benefit from the latest generation of products, with integrated Ethernet.

A printer adjusts the color mixture of the printing press. He walks up to the machine and turns the handwheel until it the desired shade of color is produced. After printing a batch of packages he realizes that the color does not match the backside of the packages. He walks up to the machine again and re-adjusts the color manually.

A scene from the past. Instead of using handwheels to set-up printing machines, compact motors are now employed. Networked via CANopen, they automate procedures that were previously adjusted manually but have become too cost intensive due to small batch sizes.

Space however is at a premium for this kind of application. The wiring between motor and drive in the control cabinet can be bothersome and is expensive. Long cables also decrease the efficiency ratio. Therefore motors with integrated motion controllers are increasingly used for space-limited and low-voltage applications such as the one described above. Where previously the electronics size did not allow the small design, controller boards in miniature size are now available. They fit within the confined space of the low-voltage motor housings. Little wiring is involved here since only a power supply and a CAN network cable are required to connect the compact drives to the network. Since no space is required in the control cabinet, the project design for the compact drives is limited to configuring the software and the power supply. Motor cables are reduced to a minimum and integrated in the devices.

“Our customers actually asked for such compact devices,” says Roland Rauch of Berger Lahr. “They were looking for a solution to reduce the number of cables and save the money on wiring. This is why we decided to develop a compact drive. In the printing industry the compact devices help to ensure reproducible printing quality. The drive in combination with a camera automatically controls the color intensity of the print media.”

Also manufacturers of PCBs need to ensure reproducible printing quality; with it the printed boards are positioned automatically and correctly.
Motors with integrated electronics are particularly suitable for the automatic setting of tools, limit stops, spindles or toothed racks, etc. They are used most commonly in wood-processing machines, packaging machines, printing equipment, filling units, medical or chemical apparatus, etc. They reduce set-up times, facilitate the control of monitoring tasks and replace the simple handwheel. External rotary transducers and reference point switches are no longer required.

Parameterizing the drive is no longer possible via a simple DIP-switch in many cases because of the sealed-off housing. If motor and electronics are both in one single housing without configuration interfaces, the baud-rate and the node-ID must be preset by the manufacturer. Another option however is the configuration via the CAN interface using the LSS protocol (CiA DSP 305).

Following are some examples of small-scale motors with integrated electronics and CANopen interface...

Numbers classify the ingress protection (IP) of electronic devices. The IP67-rated devices are totally protected against dust and the effect of immersion up to 1 m (IEC 529). This is similar to the NEMA 4X specification (details are available at www.stegmann. com/comm/protection.pdf). Also IP66K provides high protection. Whereas IP67 protects from immersion under certain pressure and time, IP66K protects from entry of water jets, the pressure of which may be considerably higher than that of water at 1 m depth.

Devices fulfilling these requirements can be used outside of control cabinets and even in out-door applications. In many machine and other control systems it is advantageous to locate the analog sensors and actuators as closely as possible to the mechanics and physics. This avoids transmissions of analog signals via long distances, which normally leads to disturbances and to errors. However, most I/O devices are not designed to operate in dusty and wet environments. The increasing demand of IP67-rated devices has lead to the development of sensors and actuators in appropriate housings (e.g. temperature and pressure sensors by Trafag and Wika). Besides single sensors and actuators, also IP67-rated devices have been launched, which provide multiple analog and/or digital inputs and/or outputs. These devices can be regarded as bus-coupler between single sensors/actuators to serial bus systems. There are several companies that offer I/O modules in IP67 housings with CAN connectivity. Some of them support CANopen (e.g. Multipurpose I/O module by Axiomatic, IP67 Modules by Beckhoff, CompactModules and SmartI/O by ifm, digsy CCN I/O (IP66K) by Intercontrol, LJX7-CSL by Lumberg, µCAN Family I/O by Microcontrol, Cube67 and MVK-C by Murr-Elektronik, WinTrak by SMA, ESX-DIOS and ESX-DIOM by STW, BL67 by Truck, SAI HP CAN by Weidmüller) or DeviceNet (e.g. IP67 Modules by Beckhoff, FieldLine I/O by Bosch-Rexroth, CrossFire by CC Systems, Cube67 by Murr-Elektronik, IP67 I/O Modules by Omron, Armor-Block by Rockwell, BL67 by Turck) or proprietary higher-layer protocols In the past the number of channels was restricted to four analog I/Os or to eight digital I/Os. Today modular devices are available that overcome these channel limitations. M8, M12, M16, and M23 connectors are normally used to adapt sensors and actuators.

Some of the IP67-rated I/O devices are designed to meet the requirements of EN 50155 dedicated to rail vehicle applications (e.g. I/O modules by ifm, Luetze, MEN, Selectron, SMA, and Wieland/Yacoub). Those products are also suitable for other vehicle applications such as mining, agricultural and forestry machines. Additionally, they may be used in truck superstructures and road construction machinery. Some of the devices consist of a base module providing the passive components and the connectors as well as the electronic module with the CAN interface and the data pre-processing unit (e.g. the BL67 series). This allows for short standstills in case of malfunctions and replacements of the electronics because the wiring has not to be removed.
Due to the fact that the user can easily add modules to CAN networks, the system can be expanded regardless of the already installed devices. There is no space limitation as in control racks. This is important for all modular machine systems that are provided in many variants.