aline.fidencio
Member
Hello guys, as requested I started a new thread. First, thanks for replying!
Just to remember, here is my first post.
"I am a student and I am trying to fix a problem with the plc5/40 communication with the AB 1771 OFE2/B. The system used to work long time ago and for an unclear reason it stopped working. One problem now, that I could find, is that the analog output is not receiving/sending information. For the BTW and BTR the DLEN bits are as follows:
BTW --> DLEN = - 7 (data was lost)
BTR --> DLEN = -5 (checksum wrong)
I was using 3 channels.. I tried moving from channel 3 to 4. Then the error was gone, but the process didn't work. (but that was okay, because i have it communicating with an inverter which i must still test - just to clarify: channels 1 and 2-> valve control; channel 3-> inverter; channel 4 -> not used so far) . But, now, the errors are back. But I dont know what can be causing them. Can you help please?"
I have some news: yesterday, I, again, turned the power off and on.. the errors disappeared! Really gone...today I had no problems again.. no error.. I really do not know why..
I then decided to check my inverter. It is a siemens 6SE3019, I used a trimpot and was able to make it change the frequency, and so, the input flow. Then, I came back with the connection from PLC Analog output, and for my surprise it also kind of worked. While in remote test I was able to set a SetPoint for the input flow and with that see the inverter responding and acting properly.
Really weird for me is: while changing SetPoint in the ladder I got:
SP Frequency
0 min freq (min flow)
2048 max freq (max flow = 40lit/min)
4095 also max freq
I tought that only 4095 would give the max frequency ...
Another problem is that the flow is too low, even for max freq. Which I set to 35Hz, even though the motor says it is for 60Hz. I did that because with 35Hz the motor starts making a terrible noise, and I am affraid of losing it. :/
Please find attached my rsp file. Sorry the comments are in portuguese. Sorry, now I have no time to translate to english, but maybe you can still handle it.
I am so sorry if I make a stupid comment. I am really new with this and basically my teacher said "there is a system there which is not working, do you wanna try fixing it?" And that was it. I have no one to change information with me or to advise me. So I am kind of making experiments and trying to learn a lot, all by myself. When I started, the plc was also with error...
The rsp does not belong to me, it was already there. So, considering that the system once worked fine, I think it is okay. But of course I have also been trying to understand it.
Thank you so much in advance.
Best wishes,
Aline
Just to remember, here is my first post.
"I am a student and I am trying to fix a problem with the plc5/40 communication with the AB 1771 OFE2/B. The system used to work long time ago and for an unclear reason it stopped working. One problem now, that I could find, is that the analog output is not receiving/sending information. For the BTW and BTR the DLEN bits are as follows:
BTW --> DLEN = - 7 (data was lost)
BTR --> DLEN = -5 (checksum wrong)
I was using 3 channels.. I tried moving from channel 3 to 4. Then the error was gone, but the process didn't work. (but that was okay, because i have it communicating with an inverter which i must still test - just to clarify: channels 1 and 2-> valve control; channel 3-> inverter; channel 4 -> not used so far) . But, now, the errors are back. But I dont know what can be causing them. Can you help please?"
I have some news: yesterday, I, again, turned the power off and on.. the errors disappeared! Really gone...today I had no problems again.. no error.. I really do not know why..
I then decided to check my inverter. It is a siemens 6SE3019, I used a trimpot and was able to make it change the frequency, and so, the input flow. Then, I came back with the connection from PLC Analog output, and for my surprise it also kind of worked. While in remote test I was able to set a SetPoint for the input flow and with that see the inverter responding and acting properly.
Really weird for me is: while changing SetPoint in the ladder I got:
SP Frequency
0 min freq (min flow)
2048 max freq (max flow = 40lit/min)
4095 also max freq
I tought that only 4095 would give the max frequency ...
Another problem is that the flow is too low, even for max freq. Which I set to 35Hz, even though the motor says it is for 60Hz. I did that because with 35Hz the motor starts making a terrible noise, and I am affraid of losing it. :/
Please find attached my rsp file. Sorry the comments are in portuguese. Sorry, now I have no time to translate to english, but maybe you can still handle it.
I am so sorry if I make a stupid comment. I am really new with this and basically my teacher said "there is a system there which is not working, do you wanna try fixing it?" And that was it. I have no one to change information with me or to advise me. So I am kind of making experiments and trying to learn a lot, all by myself. When I started, the plc was also with error...
The rsp does not belong to me, it was already there. So, considering that the system once worked fine, I think it is okay. But of course I have also been trying to understand it.
Thank you so much in advance.
Best wishes,
Aline