PT-100 temperature constantly at 2000 degrees after failure
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Something to try. Go to the GCode console in DWC and send M305 P1 X0 followed by M305 P1 X200. If it can't communicate with the chip on the daughter board, it should return an error message within a few seconds. Repeat for channel 201. If you get no errors, you can test whether the error reporting is working by trying a channel you don't have such as 202 or 203.
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Taking a step back and reading through this thread, it seems that it was all working fine then suddenly failed. Since then, you've tried a different sensor, a new daughter board and a new duet board. So how about the actual wires that link the sensor to the daughter board? That's the only thing I can think of that you haven't explicitly said has been replaced.
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Yes the error reporting is working and i get no error when calling M305 P1 X0 and M305 P1 X200 or X201 right after that. I've tried that before.
Can I somehow debug the firmware? Maybe there i can find out what the issue is.
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I really don't think it's a firmware issue, because other people (including me) are using PT100 sensors without this problem. Some users see temperature spikes to 2000C, caused by interference. That's why I would really like to know how your board behaves with just the 2 links and a 100 to 180 ohm resistor connected to the terminals.
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Ok I'm going to get a resistor next week , but I don't expect to see any difference. As i said before, i can already make sure that the resistance between 2 and 3 is of around 180 ohm and the resistance between 1 and 4 is 180 ohm as well.
How can i check if the daughter-board is actually doing anything?
As the UI shows 2000° even when no daughter-board is connected at all, I think the issue must be somewhere there. I just don't get it why it i the exactly the same with the new hardware. -
The UI will show 2000C whenever a temperature reading can't be obtained after several attempts for any reason. The difference is that when you send the M305 P1 X200 command, you get an error message if no daughter board is connected. You are not getting that error message, which means that the firmware is communicating with the daughter board.
Perhaps we should include a 100 ohm resistor with the daughter boards, to help diagnose this sort of problem.
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Well, all this because of almost nothing! Things like that always result in the smallest possible issue.
First of all I got a E3D cartridge thermistor instead of a PT100 and the second i ordered was the V6 fixing kit with contains the cartridge thermistor as well. The biggest problem is that they look exactly the the same.
The test with a 150 ohm resistor worked and gave me a result of around 130° instead of 2000°. So I ordered a real PT100 sensor and right now I'm printing all fine with the thermistor in place (logically without the daughter-board in use).Thanks for all that support.
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I'm glad you solved it.
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Thought this might be the thread to ask.
I got a daughterboard from T3P3 this morning (ordered yesterday so impressed).
I solder-bridged the pads on RTD1 carefully. I have attached my e3d pt100 (which reads 111ohms at room temp - 30 deg C!) to pins 2 and 3 on the screw terminal.
I added M305 P2 X200 to config.g
and M563 P99 H2 to tool definitions (planning to use this as chamber temp monitor until I get a heater block which can accept the sensor).
But no dice… 2000 deg C showing.
I've checked the daughterboard is properly located over the SPI pins with the bulk of the board facing in.
I've been into console and sent M305 P2 X0 - okay
then M305 P99 X200
"Error: failed to initialise RTD: bad response from sensor"Any ideas?
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Try a lower number for the P parameter not sute but pretty certain the Firmware won't know about sensors numbered that high.
Sure David will be along soon to confirm or deny my assumption?
Doug
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I'll try that sure maybe it should have been p2 or it could be something else on this board that's not quite right, but spi must work or a whole load of things would be dead which are working fine.
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Simon,
I'm using pt100s via the daughter board for my hot end and bed. The first channel on the daughter board is X200 and the second is X201 and P is the heater number.
So what you need is M305 Pnnn X200 (or X201) where Pnnn is the heater number (not the tool number). In my case I have M305 P0 X200 for the bed, and M305 P1 X201 for the hot end.
HTH
Ian
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Thanks guys. Okay so I tried M305 P2 X200 (and 201,202,203) but still Error: Failed to inialise RTD, bad response from sensor.
I will rule out the pt100 board being at fault by sticking it onto my other machine and seeing if I can initialise it.
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Okay so it works fine and reads fine on my other machine, it must be this slightly iffy duetwifi board. I won't waste any more of your time. Thank you gentlemen. Enjoy your evenings.
CalvinX looks like its back to the fridge thermometer for me
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I’m having the same issue- installed new pt100 and board and it sits at 2000.
I get 104 ohms for resistance of the PT100
2.02 volts between 1-4 on daughter board
Config file line: M305 P1 X200
Sent M305 P1 X0 followed by M305 P1 X200- no errors. No errors for channel X201 and I did get error for 202.
I’m using wire from a cat5 cable, so each pair has a slight twist to them.
They are running within a single lose bundle from the hotend to center of top of printer and down a tower leg alone. -
Okay so it works fine and reads fine on my other machine, it must be this slightly iffy duetwifi board. I won't waste any more of your time. Thank you gentlemen. Enjoy your evenings.
Do you have anything else connected to the SPI bus on that Duet, for example a PanelDue connected via a ribbon cable to CONN_SD ?
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In my case the issue was with poor quality crimping on the original e3d pt100 sensor and not an iffy duetwifi board please consider that a retraction.
I now stock pt100s without connectors with 95cm leads for less chance of a bad connection. See my signature below.
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I’m having the same issue- installed new pt100 and board and it sits at 2000.
I get 104 ohms for resistance of the PT100
2.02 volts between 1-4 on daughter board2.02V is too much. Assuming you are using a 2 wire connection, you should have the 2 jumpers fitted, in which case you should measure the same voltage between terminals 2-3 on the daughter board as between 1-4.
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I’m having the same issue- installed new pt100 and board and it sits at 2000.
I get 104 ohms for resistance of the PT100
2.02 volts between 1-4 on daughter board2.02V is too much. Assuming you are using a 2 wire connection, you should have the 2 jumpers fitted, in which case you should measure the same voltage between terminals 2-3 on the daughter board as between 1-4.
Sorry was posting from memory.
Actually using 4 wire and only see .0009 v across the terminals
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I suggest you test the daughter board, by disconnecting the PT100, connecting a 100 ohm resistor between terminals 2 and 3, and fitting the two jumpers. That should give you a reading close to 0C.
