Working with Siemens AC/DC Drives

ryanrydellCase Studies

Quantum Design, Inc. experiences and customer acceptance of applications using Siemens AC/DC Servo Drives have been received with great success. There are many reasons for this success such as identifying customer needs, proper documentation, sound documentation and configuration/programming practices to insure these high quality Siemens products provide many years of service.

One customer, a leader in coaxial cable for the telecommunications industry, which Quantum Design worked with recently, has combined AC and DC Siemens Drives to control a variety of equipment on their production floor. The end user was looking to improve the precision line speed and tension control in their continuous process as well as upgrade the existing analog based drives to the current Siemens drive platform. They also wanted to utilize a single communication protocol for all drives.

We have found the Profibus interface to be the optimal network solution when implementing Siemens drives.

Some of their drives are stand alone, interfaced through digital and analog input terminals. Others are combined and interfaced using Profibus. We have found the Profibus interface to be the optimal network solution when implementing Siemens drives. Profibus, short for Process Field Bus, is an industrial control network used to facilitate communications for factory automation, motion control, process control and safety.

The integral free blocks in the Siemens drives allow for the addition of logic and analog processing inside the drive as opposed to an outside controller, such as a PLC. Maintaining set-points such as line tension by holding a dancer position or maintaining a constant speed of payout based on changing spool diameter are examples of where using the drive’s internal PID or Technology controller to perform calculations speeds up processing and eliminates delays associated with external controller communication. This can be extremely beneficial when process speed and cable tension becomes critical.

In another application Quantum Design used an internal characteristic block to produce a speed command based on a pre-programmed set of X and Y parameters. The X and Y parameters are set by the operator through an operator interface and then downloaded to the drive via Profibus. The input to the characteristic block is the actual speed of the drive. The output of the block is used as an analog output to another piece of equipment. The Characteristic block allows the setting of X and Y parameters so that when the input to the block is within any X value the corresponding Y value is outputted from the block. This allows a non-linear speed ramp to be calculated in the drive and for the drive to function based on that calculation.

There are other freely programmable mathematical blocks that allow calculations to be performed that provide various logic functions within the drives and allow several inputs to be combined to control outputs directly. This adds to the versatility of the Siemens drives capability, while providing a range of programming options for the engineer.

The AC and DC Drives are configured using software that runs on a standard Windows PC. The parameters can be viewed and modified as required through the Siemens Drive Monitor software. The software provides built in Automatic Tuning routines to set up the drive and easily accessible parameters to set basic speed scaling. A front panel on the drive can also display the drive parameters and provide access for modification.

In conclusion, Quantum Design, Inc. has the expertise and experience to ensure success in the application of Siemens AC and DC drives for a variety of customer applications and network protocols. The Quantum Design engineering team can eliminate delays and hardware costs, increase efficiency and improve overall performance of your system.