murarisetty_apparao
Member
Hi Folks,
First time using this forum...
I am in trouble. I hope you will solve my problem.
We have commissioned one 40M long rail "Cooling Bed-C" for material transfer and tracking system in a
UNIVERSAL BEAM ROLLING MILL, in one of our client. ( Total three cooling beds are same type, in that
we commissioned one cooling bank-C, remaining banks-A,B yet to be commissioned, Total cooling bank length 120Mtrs) Each system consists of 22 Position loops having 22 DC motors with 6RA70 drives and S5-155U PLC system having
8 Nos WF-726C modules for position loops with "STEGMANN" AG-101 type Serial Absolute encoders( 4096 x 4096,SSI,Gray Code ,24Bit Resolution ).
This is basically refurbishing job, which plant removed from South Africa and installed in India.
Now for Cooling Bank-B,A, Our client supplied IFM Encoders RM6104 Type Serial Absolute encoders(8192 x 4096,SSI,Gray Code ,25Bit Resolution ), since all encoders of Bank-B,A found damaged during transport.
During Cooling bank-B position loop tuning, we find the following problems:
1. WF-726C modules are not suitable for 8192 x 4096, 25Bit encoders. In Machine Data it was not possible to define 8192 x 4096, 25Bit encoders.
2. With the same Machine Data of Cooling Bank-C, By hand rotation of IFM encoder shaft, PLC is not reading the encoder count/value gradually like 1,2,3,4,5,6,......... It was reading like 1,10,20,30.... Gradual increment reading in STEGMANN encoders.
The same query, if I ask SIMATIC HOTLINE, they replied, "IFM 8192 x 4096, 25Bit encoders will work with WF-726C modules with firmware Ver1.7". They test SIEMENS encoder of same type.
They did not answer 2nd query.
But our problem was not yet solved. During Bank-B commissioning with the SAME 'machine data' and 'automatic programs', position loop( we checked only two loops) tripped with "FOLLOWING ERROR". I tried by adjusting with "KV Factor", "Command Value","Static/Dynamic Following Error" etc. But no use, loop doesn't run proper and always hunting at the target position.
My queries are,
Why the encoder reading is not showing gradual increment during manual rotation of hand movement?
Is it really required tuning, if I change the encoder ( same specs) with other make? As per my opinion, if one bank commissioned, the others two banks also same machinery, motors, and same parameters. So same machine data should work with out tuning / changing. Is My opinion is correct?
The "IFM 8192 x 4096, 25Bit encoders" may work by doing some jugglery / adjustment with machine data, but at one point of time, three banks has to work in synchronously. Mainly I don't want to compromise the "FEED RATE" and time. If any time difference or feed rate difference occurs, the 120M rail will not transfer properly to further mechanical system. Due to this reason I suggested to our client to replace the encoders.
Attaching the machine data of 8 modules and firmware version.
Please help.
First time using this forum...
I am in trouble. I hope you will solve my problem.
We have commissioned one 40M long rail "Cooling Bed-C" for material transfer and tracking system in a
UNIVERSAL BEAM ROLLING MILL, in one of our client. ( Total three cooling beds are same type, in that
we commissioned one cooling bank-C, remaining banks-A,B yet to be commissioned, Total cooling bank length 120Mtrs) Each system consists of 22 Position loops having 22 DC motors with 6RA70 drives and S5-155U PLC system having
8 Nos WF-726C modules for position loops with "STEGMANN" AG-101 type Serial Absolute encoders( 4096 x 4096,SSI,Gray Code ,24Bit Resolution ).
This is basically refurbishing job, which plant removed from South Africa and installed in India.
Now for Cooling Bank-B,A, Our client supplied IFM Encoders RM6104 Type Serial Absolute encoders(8192 x 4096,SSI,Gray Code ,25Bit Resolution ), since all encoders of Bank-B,A found damaged during transport.
During Cooling bank-B position loop tuning, we find the following problems:
1. WF-726C modules are not suitable for 8192 x 4096, 25Bit encoders. In Machine Data it was not possible to define 8192 x 4096, 25Bit encoders.
2. With the same Machine Data of Cooling Bank-C, By hand rotation of IFM encoder shaft, PLC is not reading the encoder count/value gradually like 1,2,3,4,5,6,......... It was reading like 1,10,20,30.... Gradual increment reading in STEGMANN encoders.
The same query, if I ask SIMATIC HOTLINE, they replied, "IFM 8192 x 4096, 25Bit encoders will work with WF-726C modules with firmware Ver1.7". They test SIEMENS encoder of same type.
They did not answer 2nd query.
But our problem was not yet solved. During Bank-B commissioning with the SAME 'machine data' and 'automatic programs', position loop( we checked only two loops) tripped with "FOLLOWING ERROR". I tried by adjusting with "KV Factor", "Command Value","Static/Dynamic Following Error" etc. But no use, loop doesn't run proper and always hunting at the target position.
My queries are,
Why the encoder reading is not showing gradual increment during manual rotation of hand movement?
Is it really required tuning, if I change the encoder ( same specs) with other make? As per my opinion, if one bank commissioned, the others two banks also same machinery, motors, and same parameters. So same machine data should work with out tuning / changing. Is My opinion is correct?
The "IFM 8192 x 4096, 25Bit encoders" may work by doing some jugglery / adjustment with machine data, but at one point of time, three banks has to work in synchronously. Mainly I don't want to compromise the "FEED RATE" and time. If any time difference or feed rate difference occurs, the 120M rail will not transfer properly to further mechanical system. Due to this reason I suggested to our client to replace the encoders.
Attaching the machine data of 8 modules and firmware version.
Please help.
