Host controller and I/O modules
At the Hannover Messe, Weidmueller presented its WCU 501 controller and WCU 650 series of I/O modules. Both products provide CAN connectivity.
For automation in harsh, industrial environments, users in machinery and plant engineering or wind power systems often use expensive products with sufficiently high-temperature stability and vibration resistance. However, there is a demand for economical solutions for applications with simple control and regulation tasks, in which just few inputs and outputs are required. With the WCU range, the German cpompany is offering such products. All WCU logic modules withstand vibrations of up to 5 g and shocks of up to 10 g. The operating temperature range is between -40 °C and +70 °C.
Both WCU 501 (host controller) and WCU 650 (modular I/O) devices have multiple integrated analog and digital I/Os, various power outputs, and a PWM output. The encapsulated devices reliably monitor and control processes - even under extreme environmental conditions. The graphics programming allows flexible switching of the analog and digital inputs, as well as the power outputs. All WCU devices have a large number of predefined function blocks – the basic library covers basic arithmetic operations through to timers.
The WCU 650 module communicates with other bus users or higher-level controllers via a CAN interface supporting the CANopen application layer. For programming, the WCU devices are connected to a PC (desktop or laptop) via a USB cable. Program simulation can even be carried out with the devices connected. This software can be download free-of-charge from the supplier’s website.
The products can be used in networks with voltage fluctuations or in harsh environmental conditions, such as in the hub of wind power plants. There is even space for WCU devices in control cabinets with very limited space, said the provider. The WCU 501 measures 31 mm x 44 mm x 40 mm and the WCU 650 comes in a 30 mm x 45 mm x 93 mm housing. UL certification is in preparation. Both products can also operate directly actuators requiring power (up to 1,5 A). Due to the encapsulated PCB, the electronics are insensitive to humidity, temperature fluctuations, vibrations, and shocks.
The devices perform simple control tasks such as lighting, heating, and ventilation or motor control. Added to this are signal processing and handling, plus error monitoring. They are used in wind power systems, in photovoltaic systems, or in machinery and plant engineering.
In a "system to detect breaks in screw connections", for example, the WCU 501 performs the following tasks: it monitors the connected sensors (sensor intact/not intact) to detect breaks in nuts and, in the event of a system failure, issues an alarm signal to the higher-level plant controller.
The role of the WCU 501 logic module in wind power systems includes lighting and supply systems in the tower, i.e. monitoring the uninterruptible power supply (UPS), triggering alarms in the event of a power failure / battery mode or informing service technicians about the failure of the external power supply by means of flashing LEDs along the whole lighting train. As well as the tower system, which is the domain of the WCU 501, the WCU 650 logic module reveals its benefits in the "anti-icing system" for the rotor blades. It records measured values such as temperature, current and voltage and calculates and evaluates measurement signals. If previously defined limit values are exceeded, the heating film is also switched on in order to melt any ice on the rotor blade.
The German company also provides an optionally CANopen-connectable Protop power supply. Due to the used DCL (dynamic current limiting) technique, it offers a good dynamic range for the reliable triggering of circuit breakers and motor starters. The power supply is also designated for wind power systems and other applications with challenging vibration and temperature requirements.
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