Industry Online Support
Technical Forum
Navigation
Rating 
Thanks 3
9 Entries
| 4/30/2013 6:48 PM | |
|
Posts: 297 Rating:
|
I would guess that your axis B is not the 5th axis in the control. The PLC data block is directly associated with the axis number. See what AX number is displayed in the header when you look at the B axis using the Service Display, Service Axis in the Diagnosis area. HTH, SteveA |
This contribution was helpful to
|
|
| 5/1/2013 3:17 PM | |
|
Posts: 166 Rating:
|
Sorry it is actually 6th axis but we have checked DB36.DBX1.5 and 1.6 remain same even after bypassing external feedback, v have similar machine and there also these bits remain same with or without scale, v r sure not standard Siemens DBs but other DBs used Kindly let us know how tofind out which DB is responsible for external and motor encoder Regards M. Rishikesh |
| 5/1/2013 7:21 PM | |
|
Posts: 297 Rating:
|
If it is axis 6, then it must be DB36. There is no way to redirect that coupling. Changing the parameters in axis MD will not cause 1.5 or 1.6 to change. That must be done by the PLC to select the desired measuring system. In a properly set up control, the only thing needed to do to change from direct feedback to motor feedback is to turn on bit 1.6 and turn off bit 1.5. No parameters need change, although if the direct feedback encoder is faulty, you may need to set 30200, NUM_ENCS, to 1 instead of 2. It looks like you are attempting to define the same encoder as both motor and direct. All encoder related axis parameters have two indexes. [0] relates to motor feedback and [1] relates to direct feedback. You do not specify which index you are changing. If one encoder is considered motor and the other direct, you could have a gearing related error between the encoder paths that may cause those faults. HTH, SteveA |
This contribution was helpful to
|
|
| 5/2/2013 7:20 AM | |
|
Posts: 166 Rating:
|
Sir Thanks for ur reply a) v r unable to turnON 1.6 from PLC status as it reverts back to 0 through logic b) MD 31020(0) = 36000 and MD 31020(1) = 2048 so that means (0) is for Direct feedback (external encoder or scale) and (1) is for Motor feedback ?????? Pl calrify c) Parameters which we are changing to run on Motor encoder are as follows : MD 30230(0) =1 (1) = 1 MD 31000 (0) = 0 (1) =0 MD 31020 (0) =2048 (1) = 2048 Md 31040 (0) = 0 (1) = 0 34200 (0) = 1 (1) = 1 34100 (0) = 1 (1) = 0 32100 = 1 32110 (0) = 0 32110 (1)0 Regards, M. Rishikesh |
| 5/3/2013 7:13 PM | |
|
Posts: 297 Rating:
|
Setting 1.5 activates the first encoder, which is normally motor. Setting 1.6 on and 1.5 off selects the second encoder, which is normally direct. To usethe secondencoder, axis MD 30200 NUM_ENCS must be set to 2. It appears that your system has one encoder that was set to be direct. While not normal, it seems like it should work. Are the gearing parameters in 31050 and 21060, DRIVE_AX_RATIO_DENOM and NUMERA set to proper values? They should always be set properly, but on direct feedback only the system will still position correctly even if they are not set right. HTH, SteveA |
This contribution was helpful to
|
|
| 5/4/2013 9:24 AM | |
|
Posts: 166 Rating:
|
Thanks As informed, after we bypassed external or direct feedbac, we stopped getting error 25000 Axis B hardware fault of active encoder but we started getting error 25030 : Axis B velocity limit 1. As per siemens Help screen, we tried by changing encoder feedback to 0 and 1 in MD32110(0) and MD32110(1), switched off and on - still same error 2. As per siemens Help screen, active encoder is monitored and this error comes up if velocity exceeded MD36200 (by more than 5 to 10%), we changed it to 1.7 from 1.6 - still same error 3. Just for testing we made Number of encoders MD30200 as 0 then no error as even Motor encoder is no longer active due to this MD, control getting ON, we are able to move other axes but when we try to move B it does not move giving fault Made NCMD30200 as 2 , At the moment, B axis (tiliting yoke, which moves between -11 degress to 11 degrees) is at +ve hardware limit as machine stopped at this postion , temporarily we have given 24V DC to the input of +ve hardware limit just to avoid error related to +ve Hardare Limit - kindly advice if this extreme position is causing error 25030 and in this condition, how wrong feedback goes to CNC that velocity exceeded limt where as control not getting ON and hence B is not actually moving at all Can fault LT Modules/control cardcause error 25030 Regards, M. Rishikesh |
| 5/5/2013 8:52 AM | |
|
Posts: 2964 Rating:
|
Hello, Check the Speed setpoint cable (Bus cable) and the actual values and direction of the position control. Change the position control direction if the axis rotates uncontrollably -->axis specific MD 32110 ENC_Feedback Pol[n]=(-1,0,1) or increase the monitoring limit in the MD 36200 Axis_velocity limit ( the value here should be Threshold value for velocity monitoring; setting rule:MD 36200 = 1.15 x MD 32000) |
| 5/6/2013 9:27 AM | |
|
Posts: 166 Rating:
|
Thanks a lot for Your support Unfortunately v r not able to get through Error 25030 with or without external feedback Actaully pulley (via timer belt) on Ball screw is twice to pulley on Motor shaft MD31050 Denominator Load Gearbox (0) to (4) = 1000, (5) = 1 MD31060 Numerator Load Gearbox (0) to (4) = 424195, (5) = 1 To overcome error 25030 , we checked following : 1. Motor enocder cable from Motor side upto LT Module (1st or top slot) - Found ok 2. LT Module with Control card interchanged from drive of similar spec. 3. All the flat band interconnecting cables from NCU to all LT Modules taken out and fitted back 4. MD 32000 = 1.5 so tried bychanging MD36200 upto 2.25, MD 32060 = 27.77 changed to 1.5 5. DB36.DBX1.5 = 1 in both external encoder and motor encoder mode, same in another similar ok machine Kindly let us know how the CNC is getting feedback that velocity of B is more than limit 36200 whereas error 25030 appears just after Drives are ON ie we did not even move B axis In case of external encoder, MD 30230 = 2, MD 31020 = 18000, MD 31040(0) = 1, MD30200 = 2 (Number of encoders) In case of Motor encoder, MD 30230 = 1, MD 31020 = 2048, MD31040(0) = 0, MD30200 =1 (Number of encoders) Best Regards, M.Rishikesh |
Follow us on