PT-100 temperature constantly at 2000 degrees after failure
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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.
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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.
Sorry for the delay- took a while to get a 100 ohm resistor. I'm assuming I must have a noise issue.
With the resistor which is around 99 actual, I get -1.4C reading
I have 2 PT100s.
When connecting one of them directly to the daughter board with jumpers the reading ok, about 2C higher than bed thermistor. That PT 100 reads 108 ohm.
The other is in the hot end. When I measure resistance at the wire ends I plug into the daughter board it reads about 109 ohms.
When I turn on the printer, it reads 2000c. Each pair is twisted and running down separate towers.I have the 2 wires of the PT100 going into the hotend connector, from the connector at the hotend it's 4 wires.
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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.
Sorry for the delay- took a while to get a 100 ohm resistor. I'm assuming I must have a noise issue.
With the resistor which is around 99 actual, I get -1.4C reading
That is about right. So it looks like the daughter board is OK. Did you test both channels?
I have 2 PT100s.
When connecting one of them directly to the daughter board with jumpers the reading ok, about 2C higher than bed thermistor. That PT 100 reads 108 ohm.
The other is in the hot end. When I measure resistance at the wire ends I plug into the daughter board it reads about 109 ohms.
When I turn on the printer, it reads 2000c. Each pair is twisted and running down separate towers.I have the 2 wires of the PT100 going into the hotend connector, from the connector at the hotend it's 4 wires.
If they are twisted pairs then it is unlikely that they are picking up interference. Please check with your multimeter whether you can measure any resistance between the PT100 wires and the case of the PT100 sensor. It should read out-of-range even on your multimeter's highest resistance scale.
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Hi,
I thought i share my experience with PT100 and my Printer setup. I got random 2000 degree spikes throughout the print. It turned out to be noise from the Layer Fan which wires go thru the same cable as the PT100. Reducing the Layer Fan PWM frequency to 10Hz solved the issue and the fan still works very well.
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Between work and my son's busy schedule we're finally getting back to this, where do I adjust the fan's frequency?
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@twotone by modifying the M106 fan command in config.g for the particular fan you want to change. Frequency is controlled by the F parameter.
