5/15/2008 12:35 PM | |
Posts: 62 Rating: (2) |
I have problem in reading measuring value from FM350-2. The value that read from IW was not correct, different from directly access from FM. Moreover, the value was swing too much. I have another FM350-2 in the same network and it working good. HW configuration: CPU S7-461-3 connect to 3 ET200M, each ET200M has FM350-2. 1st FM 350-2 connect 1 encoder (2500 PPR) - good 2nd FM350-2 connect 3 encoders (2500PPR) - good 3rd FM350-2 conncet 3 encoders (1000PPR) - problem When I connect the 2nd FM with 1000PPR encoder, it's ok. I changed working OB from cyclic(OB1) to 100ms(OB35), the problem is still. I use VAT table to read IW, the displayed value is also not correct. Please see attachment for more details. Attachmentencoder.zip (219 Downloads) |
Last edited by: yuwanee at: 5/15/2008 12:44 PM |
|
5/15/2008 2:01 PM | |
Joined: 4/24/2008 Last visit: 8/2/2024 Posts: 213 Rating: (16) |
Your time window is to small for such an "small"frequency, so you will see it swing like in your case. |
|
|
5/16/2008 5:10 AM | |
Posts: 62 Rating: (2) |
Thank you Böhser_Onkelfor your suggestion, I did try to change time window. I started from 100ms -> 50ms -> 10ms. It's not worked. I changed to smaller time window because i think that PLC's CPU will get data from PIW in cyclic which upon to CPU's cycle time. So I understand that maybe CPU read data before FM350-2 update data. Maybe I'm misunderstand. I don't know how to explain, but it like the reading value is strange. While machine running at the same speed, for example 190 rpm, in commissiong screen of FM350, measuring value is about 190000 x10-3 rpm.It is good value, even the value has change +/-1000 x10-3 rpm.Butwhen i read measuring valuein program, thevaluewas swing from ~1 to~9000x10-3 rpm. So my problem is: - I can't get the correct measuring value. - Value i get is too much swing. Thank you in advance for any advise. |
Follow us on