Masterdrive MC problems

[WJhsson]

The application is consisting of two gigantic masterdrive MC:s that is supposed to be syncronized to each other. One of the drives is getting the setpoint value via profibus interface (from a Simatic S7-400). This drive is having a Virtual master running which is sending the setpoint out on Simolink. Both drives is then receiving this setpoint from the Simolink. When both drives is syncronized they run perfectly without any problems at all.

BUT.. when the power is cut off via the mainswitch for the hole machine they go crazy, i.e. they lose their syncronization. When you try to start the machine after this, the slave drive (the one without Virtual master) will enter fault state F011 (overcurrent) maybe because of to big dynamic requrements? If we now set the speedregulation in the drive to be very slow (Kp=1 Ti=1000 ms , normally Kp=20 Ti=100 ms) it is possible for the drive to syncronize once again and then it gets running again.

How to solve the problem?

1. Is it possible to set some bit in the masterdrive that is telling the drive "now you are perfectly syncronized" without doing any movement?

2. Change some parameter so the drive make nice, smooth movements to syncronize? I have tried to change the acceleration and speed parameter of the "correction movements" block but it didn't help.

Any ideas, suggestions, experiences, hints are highly appreciated.

Kindly regards
Wille

 

[L D[AR2P#0.0]]

Are you using the F01 option ?

 

[rdrast]

The overcurrent is likely due to the slave trying to instantaneously achieve it's expected position. Possibly looking at the torque limits could help, but in all likelyhood, you need to provide some means of slowly homing the slave to the master.

I don't know how the system is set up, but the slave could simply be set to go to it's target position immediately, and completely ignore the acceleration block of the correction movements block. It's been a while since I've used those drives.

 

[WJhsson]

Are you using the F01 option ?

Yes, the F01 option is beeing used.

The overcurrent is likely due to the slave trying to instantaneously achieve it's expected position. Possibly looking at the torque limits could help, but in all likelyhood, you need to provide some means of slowly homing the slave to the master.

I don't know how the system is set up, but the slave could simply be set to go to it's target position immediately, and completely ignore the acceleration block of the correction movements block. It's been a while since I've used those drives.

I have tried to set the speed and acceleration of the Compensation movements block to a minimum, but that didn't help.

 

[WJhsson]

At the moment I am using Drivemonitor to go online with the drives, but I am having a hard time using this + the Siemens function diagrams to understand the function of the drive and to see the path of the signals. Is there any other software that could give a graphical presentation of the drive configuration?

 

[L D[AR2P#0.0]]

Concerning synchronism at start up, I've got U673=B102 (a non default value), this sets the ACL integrator to the current position on the rising edge of Ready For Operation from the status word (see Sheet 836 of the Function diagrams V1.5).

When designing this system, I printed out all the relevant function diagrams and then marked all the signal paths/connections in red highlighter for future pictorial reference. You should get the designer of your system to do the same so you can follow what is going on.

 

[Peter Nachtwey]

The controller is doing what it should do

Make sure the integrator isn't enabled while the power is turned off. If so then the integrator will wind up.

Does the slave axis indicate there is an error just before start up? If so there is something wrong.

 

[JRW]

We need more info on the application. When only one axis moves- its probably too much of a load- thus the F11.

If you Can you post the .dnl file from Drive Monitor?
There is a package called DriveES Graphic, with this package you can graphically program/read Masterdrives. If you can post the .dnl I will put this on a CFC chart for you. This is not a 5 minute job, so if you post it, give me some time.

 

[WJhsson]

After a couple of days on another project I am back at this again..
Here is the .dnl files for the master and the slave. (Capstan.dnl is the master and tråd.dnl is the slave).


- L D[AR2,P#0.0]

I tried to set the U673 parameter to B102 but that didn't help.

When I used the trace function in Drivemonitor, I saw that at the first start after shutdown (setting mainswitch in off-state) I could see that the drive tried to run the motor in wrong direction for about 1ms and then change to the right direction which made the drive to enter the F011 state.

This look's like (in my opinion) that the drive is trying to syncronize / position the motor in wrong direction (I have tried to set the parameter for syncronize in only one direction instead of shortest route, but that didn't help).

The Siemens tech support is talking about changing the magnetizing current and soo on.. but I don't feel like it's in the right direction (but I have tried that to). The reason for that feeling is when the drive is up and working there is no problems at all. It starts and drives like dream! But after I have shut down the power, it goes mad.

What to do? I have tried all the things that you guys have supported me with but I don't manage to get this things working.

I think that soon I have to get some german expert here to get it working..

 

[WJhsson]

Well, just to tie up the loose ends in this topic, a couple of days after my last post (12th of february) a colleague of mine tried to solve the problem by the old "shooting from the hip"- method. In the end it turned out to be a faulty parameter that the commissioning guy from Siemens had left (5 years earlier!). It was P130 - encoder type that was given the value 3 (encoder) instead of 7 - (encoder with C/D tracking).
Thank you guys for suggestions for solving the problem.
www.plctalk.net

/Wille