Motor controller increases diagnostic capabilities for roller conveyor systems

With the high IP67 protection range, Beckhoff’s EP7402 EtherCAT box compact motor controller for BLDC motors is suited for conveyor tasks in intralogistics and assembly technology, as well as in the packaging, food, and beverage industries.

It has a plethora of features that excite Beckhoff ’s IO product specialist, Supriya Suhale, who knows the product inside out.

“The great thing about this product is that we have designed it to be vendor agnostic. A lot of roller drivers in the market are specifically designed for their own motors,” she said.
“A lot of system integrators utilise motors from more than one manufacturer, interoperability makes it easier to expand. Even if it were not planned during the commissioning, our solution will fit right in. It is a real team player.”

The EP7402 takes over the control of a roller motor independently of the conveyor or motor manufacturer. The control of the motor is sensorless. Maximum rated current, acceleration or deceleration ramps and various other parameters can be configured, allowing optimal adaptation to different applications.

“A trend we see by some motor roller manufacturers is to integrate the drive into the roller together with the motor and gearbox,” said Suhale. “However, we feel this leaves the customer at a disadvantage, as it requires a PLC with analogue outputs for motor control.

In the age of Big Data and predictive maintenance, having a PLC that directly controls the motor will provide a clear understanding of the motor conditions and provides important feedback across EtherCAT to the PLC. By treating a MDR as an extension to the EtherCAT bus, Beckhoff can quickly and easily control and expand on this roller network.”

In conveyor operation, the EP7402 can also be operated without a PLC and provides functions such as Zero Pressure Accumulation (ZPA), single or block discharge.

It is IP67 protection rated and can be mounted in standard C‐channel or L‐brackets on the conveyor frame. It requires no additional protective covering, which saves additional installation space.

“Commonly we come across products that are IP20-rated or IP54-rated,” said Suhale. “The EP7402 offers IP67 protection and uses connectors for optimal durability, longevity, and flexibility. This also ensures that the EP7402 meets new standards in the USA for protection of low voltage circuits, NFPA79.”

The protection has other strings to its bow, which is handy for those who are looking to make their conveyor systems more user friendly.

Routinely the cases/bins are introduced by dropping them on a running conveyor. Or in the case of a jam, operators often must push the cases/bins back against the direction of the conveyor flow. This creates a great deal of back EMF, according to Suhale. The EP7402 offers optimal protection against back EMF. In cases where this is extraordinarily high, Beckhoff offers a solution for absorbing and depleting further energy. This eliminates the frequent MDR failures common throughout the industry which creates downtime. The EP7402 offers further protections not typical of other products in the industry including protection against high ESD and over-voltage conditions, with both electronic resettable fuses and standard fusing.

Suhale also points out that the EP7402 is easy to install and more than one can be used at a me.

“The EP7402 does not use proprietary configuration software for configuration, nor dip switches for configurations, instead it is parameterised across EtherCAT using central configuration for the whole system, where values can be saved in the TwinCAT project on the machine controller and sent down to the EP7402 upon start-up,” she said. “Dip switches are a significant cause of down-time from unintended changes of the dip switch configurations. Parameterisation stored in the TwinCAT project also allows for quick change-over in the event of a replacement since no parameterisation is required prior to the replacement.”

“The EP7402 makes use of all the benefits EtherCAT technology has to offer. It provides maximum topology flexibility and redundant network.

EtherCAT devices such as digital and analogue I/Os, barcode readers or safety devices can be connected to the additional EtherCAT junction allowing compact integration and comprehensive current/voltage diagnostics”.

Because of the popularity of the devices, Beckhoff is looking at producing other iterations within the market.

“Currently we have released the version of the EP7402 with EtherCAT communication Going forward, we are expanding the portfolio with EtherCAT P (EtherCAT and power in a single cable) and an EtherCAT‐less version to support legacy field bus systems,” she said. “On the road map we are looking at a 48 V possibility soon.”

Other features include two outputs with integrated motion controller for the direct connection of 24 V DC conveyor roller motors or other BLDC motors (up to 3.5 A). Eight additional digital inputs/outputs enable connection of, for example, photoelectric switches and communication between the different box modules in opera on without a PLC.

Finally, the power supply and EtherCAT communication take place via a single cable with a B23 ENP hybrid connector (28 A/45 °C current carrying capacity).