Stop the presses!
Centraalstaal BV produces aluminium and steel building kits for the shipbuilding industry as well as complex architectural projects. Centraalstaal specialises in the numerically-controlled cold bending of profiles and 3D forming of shell plates.
In order to extend the service life of a shipbuilding press, Centraalstaal took the decision earlier this year to replace the old S5 PLC press control system with an S7 PLC. ES Elektro Groningen had already worked with Centraalstaal previously on a retrofit of a 500 tonne shipbuilding press. As the advice offered then was successful, Centraalstaal asked ES Elektro to be involved once again in the production of the next press.
An additional request for the next press was to have the operation control panel operate wirelessly on batteries. This was needed in order to provide a greater level of safety on the work floor, as cables can be sensitive to breakdowns and can (literally) represent a stumbling block. Furthermore, the steel plates can sometimes be twelve metres long and three metres wide. This means that the operator cannot see the other side of the plate during the forming process. The panel must therefore be able to move around the entire plate, however the length of the cables can be a restrictive factor here. A wireless connection makes the task much more flexible for an operator: all operating features are integrated into a touch panel, with the exception of the hoist and cranes operation. The reason for this is that a gear stick gives the operator a better feel for the machine. "We usually take care of the modification of a press ourselves, taking a step further towards modern technology each time. In this case, however, the step was a bit too great for us to take as we wanted to make the operation wireless. That is why we asked ES Elektro to be a part of the process", notes Xander Smith of Centraalstaal's Technical Service.
"We were initially planning to use a wireless network connection with a Safety PLC to achieve this, until ES Elektro advised us to avoid that as safety signals are not allowed to transmit through a standard wireless connection", Xander Smith explains. ES Elektro called on itsme Industrial Automation to provide help with this. "We wanted to integrate the safety features into the PLC. In order to avoid using a Safety PLC for an individual safety feature, I advised them to opt for a Phoenix Contact safety solution. This works without a Safety PLC yet can still be integrated into a PLC system. Such a solution can be better scaled without major investment", explains Bram Oostenbrug, Technical Sales Adviser at itsme Industrial Automation.
As an emergency stop needed to be fitted into the control panel, this would have to be linked to the main system via a wireless connection. Phoenix Contact has a wireless solution through which Profisafe can be transmitted, based on Bluetooth technology. The SafetyBridge technology (Factoryline Wireless Bluetooth Ethernet Port Adapter set) operates independently with each PLC manufacturer. With this system applications up to PLe and SIL3 can be attained. The configuration of the secure input and output channels and creation of safety logic using pre-defined function building blocks is provided by SAFECONF software. The SafetyBridge technology is integrated into the Inline I/O system provided by Phoenix Contact. No special main station is needed and the secure input and output channels can be adapted to the relevant application in a flexible way. Data transmission from the secure input module to the safe output module is controlled using a special protocol.
In order to ensure the operation and reliability of the wireless system, Phoenix Contact carried out a small test on site with the bluetooth modules that would be used. The test was so convincing that it was decided there and then to go for the proposed solution. "It was simple, meaning we would not need to attend a course. It was also faster. You could call it mere child's play!" recounts Xander Smith.
However, the process ran somewhat less smoothly than expected, as a long lead time was necessary. The time gained thanks to this solution was therefore limited. "itsme Industrial Automation supports customers along with the itsme companies involved in industrial technology. Being a trendsetter, we occasionally take on something of a pioneering role, which means that we are thoroughly underpinned theoretically, but in terms of practical experience with the innovative SafetyBridge technology we were lacking. When you are a front runner, you sometimes need several different parties to achieve success on complex projects. And that is not a bad thing, as in the end you are all successful together", says Bram Oostenbrug. itsme Industrial Automation and Phoenix Contact collaborated intensively on this project in order to overcome the "problems". itsme Industrial Automation simulated the situation at its help desk in Raamsdonksveer and Phoenix Contact was available at Centraalstaal for support on site. "Fortunately, the confidence that it would all work out was always there", notes Xander Smith. And that appears to be true: this very month the new wireless operation of the shipbuilding press is being put into operation!