Strange DC Motor Control

Hi,

We have a packaging line containing a foil wrapper. (Power Pack manufactured by EPI strech 2000/01).

During packaging, the plastic foil is drawn between two toothed rollers (diameter + / - 50 mm, length 50 cm). The foil wrapper is equipped with a detector that either measures the distance to a corner of the object to be packaged, or detects the presence of an object to be packaged.

The correct operation is unknown to us.

The toothed metal rollers are driven by a DC motor, which in turn is controlled by a DC motor speed control 0-210V / 3 A (manufactured Tymic11).

This DC motor speed control is defective. The packaging line is now 10 years old and there are no spare parts available anymore. From the manufacturer, we get very little cooperation.

Does anyone know a Tymic 11 dc motor control? This control is provided with the following inscription:

EPI PACK 15300002
Uin (220VAC)
Uout (0 ... 200 VDC)
I out (max) = 3.5A

control pulse time 0.1 - 2.5 S
digital inputs (24 V AC / DC opto coupler)
digital outputs (opto - NPN)
U senz (0-10 VDC)
supply for PNP (PNP on / off)
soft start 0 ... 3 s

terminals
A …..PNP……….......(to sensor (sensor output))
B …..0v ……………...(to sensor (negative supply))
C …..U senz….……..(not connected)
D …..220V AC .…….(230 VAC power supply)
E …..220V AC ………(230 VACpower supply)
F …..20 V (text damaged)…..(to sensor (positive supply))
G …..++ 24V ….....(not connected)
H …..+ M …..........(to DC motor)
J ….. - M …..........(to DC motor)
K ….. OUT…..........(not connected)
L ….. IN ….....….....(to PLC (PLC output ???))
M …..++ 0V…........(to ground control circuit supply)

Who knows the working principle of a foil packaging machine? In other words, is the DC motor used as an adjustable brake to strech the film (torque control) or is the DC controller only used to control the speed of DC motor (speed control)?

On the same device there is also a frequency-controlled AC motor.

If the DC controller is only used as a one quadrant speed controller, I suspect that the manufacturer would have chosen for two inverters instead of a DC controller.

A breaking resistor is, at first sight, not present in the device.

We did a current measurement between the DC motor and controller.

If the current was constant, we could conclude that the DC motor has been used as a torque motor. (It is a permanent magnet DC motor)

Unfortunately, the current fluctuated continuously.

We also did a voltage measurement on the terminals of the DC motor. If this voltage would be constant, we could conclude that the DC motor is speed regulated. But also the voltage fluctuated constantly.

There's no tacho or encoder feed back between DC motor and control Tymic.

Who knows what to do?