Parker COMPAX series compact servo controller: integrated motion control and drive

4.4 COMPAX XX70- Electronic Cam Control

This is the most powerful software variant in the COMPAX series, designed to electronically replace mechanical camshafts and camshafts. The system collects the real-time angle of the spindle through an incremental encoder, and COMPAX calculates the target position of the spindle based on the cam curve set by the user - stored in non-volatile memory in the form of up to 2500 reference points - and drives the servo motor (synchronous or asynchronous) to accurately follow. The controller performs linear interpolation between reference points, with a repeatability accuracy of up to 0.02 degrees. Multiple cam curves can be stored simultaneously and support dynamic switching of external signals, achieving the function of "curve linking".

In addition to position following, each reference point can also be associated with auxiliary functions: simulating the travel switch or analog feedback on the mechanical cam through 8 digital outputs and 2 analog outputs (± 10V range). Users can use the "CamEditor" Windows software to create cam curves graphically. After entering key points, the software automatically interpolates and displays position, velocity, and acceleration curves. Auxiliary functions can also be intuitively assigned on the timeline. In addition, XX70 provides multiple engagement/disengagement modes: static engagement, engagement at a designated synchronous position through external signals during spindle rotation, or automatic engagement when the spindle reaches a specific angle. The system also has a "lag warning" function, which outputs an alarm when the deviation between the actual position of the axis and the theoretical curve exceeds the set value. For complex curve design, Parker's technical support department can use the "Optimus Motus" design tool to generate optimized curves, balancing acceleration requirements and motor power. This variant is particularly suitable for reciprocating sealing and cutting machines in packaging machinery, die-cutting machines, and electronic jacquard weaving in textile machinery.

Flexible communication and bus integration

The COMPAX series provides a wide range of interface options for integration into modern industrial networks. All models come standard with an RS232 serial port for parameter settings, program downloads, and point-to-point control, with communication rates of 9600 or 4800 baud. For multi axis systems, users can choose from the following bus interfaces (all with optoelectronic isolation):

RS485: Supports 2 or 4 wires, up to 115k baud, and up to 99 stations.

Interbus S: Twisted pair remote bus, 500k baud, with a maximum of 64 participants per loop.

Profibus DP/FMS: 1.5M baud, compatible with Simatic S7 module.

CANbus/CANopen: up to 1M baud, following the CiA DS301 communication protocol and DS402 driver specifications.

CS31: Dedicated to interface with ABB PLC.

In addition, the HEDA real-time interface (options A1/A4) is a synchronous serial real-time bus that enables high-precision synchronization between the COMPAX master station and up to 16 slave stations, with a synchronization accuracy of ± 2.5 microseconds. HEDA can be used to transmit position settings or actual values between multiple axes, or to connect with HAISER's interpolation module (IPM) to achieve interpolation and tracking of up to 9 axes and 100000 contour points, with a data exchange cycle of only 1 millisecond.

For digital I/O, the standard configuration provides 16 channels of 24V DC input and 16 channels of output (8 channels each for 1000SL), with short-circuit protection for the output and a maximum of 100mA per channel. All I/O are connected through pluggable terminals. In addition, 5 binary inputs/outputs are provided for programmable controller data interfaces (excluding 1000SL). The encoder interface (standard or optional) supports RS422 differential input, can be connected to incremental encoders with 120 to 5000 lines/rpm, and has encoder simulation output (512 or 1024 pulses/rpm). Absolute position detection can be achieved through either a Resolver (standard configuration) or a SinCos encoder (options S1/S2/S3), the latter supporting single or multiple turns (4096 turns) absolute values. Option S2 also has a programmable transmission ratio, while S3 is suitable for linear motors.

EMC measures and peripheral accessories

To meet the requirements of CE certification (EN61800-3) and electromagnetic compatibility in industrial sites, COMPAX provides a complete EMC solution. The AC inlet filter (models NFI01/02, 01/03, 01/05) is used to suppress RF interference and meet the conducted emission limits. The connection line between the filter and the driver should be as short as possible: the unshielded line should be less than 0.5 meters, and the shielded line should be less than 5 meters. When the length of the motor cable exceeds 20 meters, a motor output filter (MDR01 series) must be installed, and the specifications of 16A/2mH, 30A/1.1mH, or greater than 30A/0.64mH should be selected according to the rated current.

The processing of regenerated energy is an important part of servo system selection. COMPAX models are equipped with different capacity energy storage capacitors and discharge circuits, but continuous or frequent deceleration processes require external braking resistors. The selection guide is as follows: COMPAX 1000SL recommends BRM8/01 (100 Ω, 60W continuous, 253W peak); 25XXS recommends BRM5/01 (56 Ω, 180W continuous); 45XXS/85XXS recommends BRM6/01 (22 Ω, 450W continuous, 6.9kW peak); 35XXM recommends BRM7/01 (10 Ω, 2kW continuous, 56kW peak); Choose the BRM4 series (15 Ω, providing continuous power from 0.57kW to 1.5kW) for the NMD20 power module. All braking resistors are equipped with 1.5-meter connecting wires, with a maximum allowable extension of 2 meters.