Siemens Traversing Block Problem

[Manoj M]

Dear Experts,
I wanted to discuss a problem which I am going through now and you experts can suggest me a solution for this.
I am using S120 servo's and using traversing to control the positions of the servo. The problem is every now and then, I am losing the Traversing Active signal from the drive and that cause no motions to servo. I can see that there is right traverse block number being fed to block plus also there is this bit activate Traversing Task which goes high but as I mentioned earlier, I am losing the Traversing Command active, which I believe comes from the drive status word.
Can somebody explains me how to trouble shoot this.

Many Thanks in Advance
Manoj

 

[JRW]

Too many things to guess...
Set up a trace for digital signals
I assume your not getting any alarms? it just stops?
Are you calling the tasks from the plc? (I see your using 2091.x for traversing block selection)

 

[Manoj M]

Thanks JRW for responding.
The traverse move number is active via 2091.x and also there is no alarms in the drive. Yes you are right, I am calling the tasks from the PLC.
I will give a try with Trace and see if that works.
Will post the outcome of it.

Regards
Manoj