Murrelektronik’s unmanaged switches standard in HandlingTech robot cells
Automation specialist HandlingTech develops and implements modern modular handling solutions for industrial manufacturing sites. In its sophisticated robot cells, the company’s unmanaged 8-port and 16-port switches “make the networking of Ethernet nodes uncomplicated and compact”, it states.
For its automation components, the company relies on external partners that provide them with time-tested, future-proof solutions and systems. Murrelektronik has been HandlingTech’s proven partner for many years.
Marco Balzuweit, HandlingTech’s electrical designer, says: "The collaboration started by using Murrelektronik's Exact distribution boxes to bring data from field sensors into the control cabinet. Their implementation was followed by various power supplies – currently, we are using Emparro switch-mode power supplies.
"Most recently, HandlingTech made the decision to use Murrelektronik products for the I/O distributors in the control cabinet. We selected Cube20S I/O systems, which combine digital inputs and outputs into one cell and bring them back to the bus node. We have also made use of Murrelektronik's extensive range of connection technology products."
Compact and affordable
Since the beginning of 2019, Murrelektronik switches have been installed in HandlingTech's standard robot cells. The ‘door openers’ were the Xelity 8 port unmanaged switches. Push-in terminals for the power connection simplify the wiring of the individual switches. The devices prioritise PROFInet protocols and thus prefer PROFInet data over Ethernet data. Xelity switches can transfer data packets at speeds of up to 100 Mbit/s.
Henning Schultz, electrician and electrical designer in the production department at HandlingTech, was sold on Xelity switches literally at first sight: "The compact design of the Xelity 8 port is super. Their small size allows them to fit easily next to a power supply, contactor or relay, without having to create extra space on the DIN rail or in the cable ducts.
"I also find the push-in terminals very practical as many competitors still have an additional plug with screw caps, which complicates the connection. Size, feel, function and price of the Xelity switches make them a well-rounded product."
Not only are new plants equipped with the Xelity switches, but older ones are as well during retrofitting. Many older plants have Ethernet as the standard are not yet equipped with a bus system therefore HandlingTech’s electrical engineers have repeatedly integrated these switches during retrofits at the customer’s request.
Nancy Locher, Murrelektronik sales engineer, adds: "In a retrofit, space is often the limiting factor. The compactness of Xelity switches is a big advantage here."
Two switches per system
Henning Schultz again: "We provide two Xelity switches standard for each robot cell, in order to separate Ethernet and PROFInet whenever possible. Even if only four or five ports are occupied – in the highest expansion stage, we need all of them. It is also important for us, as well as for the control cabinet builders, to have a certain design standard. Murrelektronik switches are now part of almost every installation of ours."
The industrial PC, the robot, and the safety and remote maintenance systems are connected to the switch via an Ethernet TCP/IP interface on the outside of the control cabinet so that it does not have to be opened for service work. This means that the majority of the ports are occupied, leaving one or two ports as a reserve, for measuring tasks in the cell.
Eight and eight are not sixteen
Xelity switches can reach their communication limits when large amounts of data are involved. This is where Murrelektronik's Tree16 TX unmanaged switch comes into play. The 16-port unmanaged switch has two Gigabit Ethernet uplink ports and 14 Fast Ethernet downlink ports.
Dennis Zimmer, Murrelektronik’s product manager - Switches, explains the difference between these 16-port switches and competitor’s solutions, which consist of two interconnected 8-port switches: "You would think that eight and eight are sixteen. But that is definitely not the case in this instance. The connection between the two 8-port switches is not designed to handle large amounts of data. Our device is a pure 16-port switch with a matching controller chip. The composite switches may be less expensive, but our 16-port switch is reliable and has the necessary power."
Marco Balzuweit of HandlingTech emphasises: "We haven't had any failures with Murrelektronik's 16-port switches."
Especially in special machine solutions, where several large robot and processing modules are networked together, there are always cases where the Gigabit ports on the unmanaged 16-port switches are needed. One example is a large system for machining shafts, where a machine tool is positioned between two robot cells from HandlingTech.
The first robot station is tasked with removing the workpieces from a grid box and loading the machine tool. The workpieces are fed to the system via a grid box in which the shafts are randomly placed. The robot uses path planning based on a point cloud to grip the components. A point cloud is generated based on data from a vision system above the grid box to calculate the best approach point for the robot gripper.
The robot, equipped with an interchangeable gripper system, picks up the component with a magnetic gripper and deposits it on a clipboard, where it is aligned. It then loads the tool to machine the part. The robot in the subsequent cell unloads the machined shafts from the tool and packs the parts directly into cartons with a blister layer.
The camera data is processed autonomously on a separate computer. In this system, the 16-port switches are responsible for the communication between the robot systems. The two gigabit ports ensure communication with the higher-level controller, while the remaining 100 Mbit ports collect data from the various participants in the cell.
Strong also in support
Henning Schultz also sees Murrelektronik as an asset in another important area: support. "If I have a technical question or a problem, I can get a product engineer or an application engineer on the phone quickly. In special machine construction, where orders are also won via delivery time, immediate response is important. When I need quick help, I get it at Murrelektronik. In addition, Murrelektronik only releases market-ready products."
Murrelektronik product manager Dennis Zimmer responds: "When a product is close to completion, we take it to customers to get their feedback. We presented the Xelity switch to HandlingTech in advance. Our customers know the product requirements best and tell us what is good and where something can be improved. It's kind of a joint development with the customers."
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