LinMot - Servo Controllers

LinMot-E is a family of modular servo controllers that are derived from each other. The user can chose between units in various performance classes for up to four different, independently controllable motors. Linear motors from various LinMot families can be connected to the same controller as well as standard two-phase stepping motors and solenoids.

LinMot servo controllers are normally used as drive controllers. Using signals from an overlaid control system, the motors are driven to the positions required. This action can be combined with the use of integrated motion profile curve functions. This allows jumps in set points to be carried out in a non-jerky and gentle manner. Customised functions, complete sequential control or PLC functions can be integrated into the servo controller using application software.

The configuration of the LinMot-E servo controller is done on a menu basis using the windows-based LinMot Talk PC-software. LinMot Talk also assists the user when commissioning the drives: On-line measurements of motor data and movements made by the controller can be shown in graphical form and stored on a PC.

Modes of Operation

Depending on the type of LinMot-E servo controller, various different modes of operation are available. The modes of operation define the control interface, the method for defining set points and how error reports are handled by the overlaid control system.

Analogue positional set-point
For the analogue setting of positional set-points, the supervesory controller passes down the set-point directly as an analogue signal. In the servo controller, the working range is defined by allocating positions to the maximum and minimum input voltage. By inputting the appropriate voltage, any position in the working range can be reached.

Two-point operation
In two-point operation, two end positions can be reached by using a digital input signal. The two end positions are configured in the servo controller and can be chosen at will. This mode of operation allows pneumatic cylinders to be directly replaced: instead of the valves, the servo controller is controlled by digital control signals.

Running motion profiles (up to two)
In this mode, two freely defined motion profiles per drive can be called up. The profiles, which are stored in the drive electronics, are run on the rising and falling transitions of the digital input signals.

Running motion profiles (up to sixty-four)
This mode allows up to 64 various motion profiles to be defined per drive. The profiles, which are stored in the drive electronics are started by addressing them via the digital input signals.

Programmed sequences
Complex motion sequences are laid down on a step-for step basis in a table. The instructions stored in the drive electronics are worked through one by one via digital input signals or are directly addressed individually.

Teach-in
When configuring the servo controller, the positions targeted are laid down in a table. In the teach-in mode, the slider of the linear motor is brought by hand into the position required and the current position stored in the table. The positions stored in the drive electronics are called up via the digital input signals.

Controlling stepping motors
In the stepping motor mode, one motor per controller can be positioned using two digital signals from the overlaid controller. The first signal defines that a step should be carried out and the second defines the direction of motion. Step values can be configured to the values required.

RS 232 serial operation
The overlaid controller can communicate with the servo controller via an RS 232 interface. Using an ASCII protocol, set-point positions can be directly defined or motion profiles that are stored in the servo controller can be run. The serial interface makes it possible to call up current values such as the actual position or the motor current of the linear motor. A detailed description of the ASCII protocol and the commands available can be found in the annexe.

RS 485 serial operation
Via an RS485 interface, up to 6 servo controllers can be connected to the overlaid control system. Using the ASCII protocol the same functions ca be activated as with the RS 232 interface. A detailed description of the ASCII protocol and the commands available can be found in the annexe.

PROFIBUS DP field bus
Using the PROFIBUS DP interface, up to 125 servo controllers can be integrated into a field bus system. The standardised PROFIBUS DP system allows the direct definition of positional set-points, as well as the running of motion profiles stored in the servo controller. The connection via PROFIBUS DP makes it possible to call up current values such as the actual position or the motor current of the linear motor. The standardised PROFIBUS DP field bus interface guarantees trouble-free commissioning and reliable operation with control systems from different suppliers.

CAN field bus
The CAN field bus allows the operation of up to 32 servo controllers in a field bus system. As no standardised protocol for all control systems is available, protocols are integrated on a customer-specific basis. Basically, all the standard functions can be implemented as is possible with the with the ASCII command described in the annexe.

Synchronisation with main shaft / Encoder follower
When mechanical cams are to be replaced or in applications where the linear motor is to perform motions synchronised to a main shaft or to a master drive, the Master Encoder Interface is necessary. The Master Encoder Interface allows the synchronous running of motion profiles that are stored in the servo controller. The overlaid control system only has to indicate which profile is to be implemented.

Synchronisation / PROFIBUS DP
The synchronisation with a main shaft or to a machine drive is possible using the PROFIBUS DP interface. The synchronisation signals are provided over the Master Encoder Interface and the required motion profile is selected via the PROFIBUS DP interface.

Force control
For the integration of linear drives in machines with positioning cards from third-party suppliers, the motors can be driven in force mode (cf. torque mode in rotary drives). In force mode the LinMot-E servo controller is controlled using analogue force signals via the position control card. For this application, the force control software is needed (see annexe)