Driving towards a safer future
May 1st 2005 Part of its L-force concept Lenze recently launched its 9400 servo drives. Ian Clay got a sneak preview of the products at the Hanover Fair in Germany prior to their UK launch
Lenze’s integrated L-force concept embraces motors, geared motors, servo drives and field devices such as I/O and remote maintenance modules.
Software is also an important part for logic and motion control, with drivebased and PC based solutions. The newly launched 9400 servo system is the leading product in the L-force ‘family’ that according to product manager, Geoff Janes “demonstrates consistent engineering throughout the range”.
The drive range is a universal concept for use with single and multi-axis applications and with a large range of operational voltages. This results in drives that are able to work with differing power supplies in applications Worldwide. Modularity and scaleability is a fundamental characteristic of the 9400 servo. This means that services, functions, software and communications can be combined in a precise format as required by the customer, or as Geoff Janes says “Because of the modular nature of the drives our customers pay for what they need, not what we think they need.” One area where the 9400 stands apart is the simple mechanical mounting of the backplane installation concept. The backplane handles all the high voltage connections and is separate from the drive. Installers will mount the backplane into the control panel, connecting the power supply, the DC bus if required and connections to the motor. Set up is made easy by having an integrated RFI filter and optional plug-in braking module.
Once all the high voltage connections are made, the drive itself can be manually placed onto the backplane and locked into position, a process that takes only seconds. I can personally vouch for this claim as, under the watchful eye of applications engineer Ben Davis I disconnected the drive from the backplane, removed all the plug-in modules and successfully re-locked the drive into position all fairly smoothly. The backplane concept can lead to further savings in maintenance and the assurance of less downtime should there be a failure. This point reinforces Lenze’s tag line for this product – ‘Your future is our drive’ – with Geoff Jane’s taking the straightforward example of “If you are making beef burgers, just think how quickly you can be up and running again in the unlikely event of a failure.” Drive-based safety One of the most important factors of the new product is the inclusion of plug in safety modules, these offer drive based safety, reducing component count, cutting costs and giving faster response to safety signals. Two plug in safety modules cover safe stopping plus five other safety related functions together with communication on a safety bus. Elements such as stop switches and lightguards can be connected directly to the drive and the requirements of IEC/EN 61508 SIL 3 are met. With safety built into the drive, there is no longer a need to specify a number of different safety relays and monitors for use with emergency stop switches, light curtains etc. The drive is the critical for considerations of machine safety, as only the drive can cause unwanted powered rotation of the motors. Ever increasing safety requirements have led to an array of sensors and isolators external to the drive. Now the 9400 servo offers plug-in modules, that allow the higher standards of safety to be met without external controls. This concept will place machinery and plant constructors in a position where they are able to dispense with external evaluation and isolation devices, because the sensors can interact directly with the integrated safety functions in the drive. Increased safety from short disconnect and fault reaction times are a direct result of this. The scope of functions ranges from standstill functions such as safe stop and safe standstill, through motion monitoring including safe speed reduction and safe push button control, to safe inputs and outputs. Safety bus systems such as PROFIsafe can be used Communications Increased communication ability and greater flexibility are a feature of the 9400 servo system. In addition to the CANopen system bus, a Lenze standard, the 9400 TopLine models can also accept two additional communication modules. All of the relevant bus systems currently on the market are supported.
The user has a total of four serial, simultaneously functioning interfaces in addition to the standard on-board diagnostics interface.
A particular feature of the system worth mentioning, and perhaps even an indicator of a technological step forward is the Ethernet in the drive. The ETHERNET Powerlink module (along with a standard Ethernet module for non real-time applications) gives product or motion control applications their real time requirement. ETHERNET Powerlink is a communications protocol, through which 240 units can be connected, for the expansion of the standard IEEE802.3 fast Ethernet) for automation tasks, that have a requirement for hard real time.
Due to a concept of clean expansion, standard Ethernet controllers, infrastructure components and network analysers can be used.
An important part of the L-force family and integral to the successful implementation of the new servo drives is the L-force software. Applications engineer Ben Davis says “Our approach to the software is that it must be intuitive and with our products Wizards guide users through the drive set-up process”.
During a demonstration Ben, through the simple example of a three axis system, showed how different parameters can be changed quickly and easily without any programming but with ‘instant’ results to the direction of the motor.
The new Lenze 9400 servo system is available initially in a power range from 0.37 to 11kW but will soon extend up to 400kW. Highly dynamic synchronous servo motors or asynchronous models with a wide speed range are also available from the Lenze factories to match the drives. The new servo system offers innovative features such as plug-in modules and the backplane installation.
Drive based safety offers further savings in external controls while achieving higher performance. The L-force concept adds usability with communications, services and advanced run time software. More articles from Lenze Ltd: | 
