MVK Metal provides complete fieldbus solution for debarking system

Murrelektronik’s rugged MVK Metal Profibus fieldbus solution provides unbeatable reliability and flexibility for German machine builder Halder GmbH and their mobile debarking system.

Machinery used in the forestry industry has to be extremely rugged, including mobile debarking systems that operate in wooded areas in southern Germany. When it was time for a major retrofit of Halder's debarking system, they knew that they wanted a Profibus fieldbus solution that could handle the demanding rigours of machines that operate for approximately 1,200 hours a year.

MVK Metal provides complete fieldbus solution

Murrelektronik’s MVK Metal fieldbus modules, with their rugged housing of components and multi-function ports, were the obvious choice. “This provided flexibility. We could use and configure the individual ports as input or output, according to the specific requirements”, explains Alois Öhler, a control technology specialist from R&Ö.

In the end, a complete fieldbus solution was implemented with a relatively small number of modules. If a port is not used, it is sealed with a blind plug. However, this doesn’t happen often as most of the ports are used twice, most commonly for double valve connectors that control the hydraulic pumps.

The integrated hex thread on the M12 cordsets is another advantage for Halder. They are able to accurately tighten them with the torque wrench and quickly loosen them for repair work.

Automatic topology discovery

Another advantage of the MVK Metal fieldbus solution is that the machine operators are able to troubleshoot problems themselves. “If it should happen that a fieldbus module doesn’t work, they can take a spare module, set the correct addresses, and replace the defective module”, explains Berthold Halder, President of Halder.

The automatic topology discovery does the rest. This avoids abandoning an operation or having to do troubleshooting on site – not that either happens very often.

“To be honest, so far there was only one failure with a Profibus connection that interrupted the fieldbus system, and this was caused by inappropriate use,”

says Berthold.

High density compact components

Another project – installing a display in the driver’s cab to easily use MVK Metal’s diagnostic options – has already been initiated. In the vehicle’s operator cabin, and in some smaller decentralized cabins of the mobile debarking system, Murrelektronik’s Cube20s system has been installed.

“There isn’t much room in these cabins. Therefore it is very important to install high density compact components”, says Berthold. “Like the MVK Modules, these modules are also exposed to vehicle shock and vibrations”, he adds. This isn't a problem, however, as Öhler explains: “The wires are connected to vibration-resistant spring clamp terminals to make a safe connection.”

Murrelektronik’s buffer module MB Cap

Another important point for Halder is that the fieldbus solution is continuously supplied with power. Because, when the motor is started, the generator needs a lot of power. This is always a critical moment as “it can happen that voltage is interrupted for a brief time, in the worst case scenario even for a few seconds”, says Berthold. Thankfully Murrelektronik’s buffer module MB Cap helps to protect the 24V supply of the control and the fieldbus system.

In the end, Halder has been very satisfied with Murrelektronik’s products and solutions. “It is important for us that the machines work and we aren’t standing in the rain, in the woods, having to look for failures”, Berthold concludes. With Murrelektronik's reliable fieldbus solutions, they needn't worry.

For more information please visit www.murrelektronik.uk.