Error Check Sum

I keep getting an red line in the Log at the bottom during initialization that says Error: Check Sum. What exactly does that mean?


  • That error in this writing does not exists, but I assume you mean the checksum test when host/server send commands. They also send a checksum to verify that command was received correctly. The error indicates a communication error since the checksum was wrong. If that happens only every x 1000 lines it is no problem and can be ignored as it gets corrected automatically. Especially on connection start it seems to happen frequently.
  • Okay. So I just attempted our first print. What it said was communication error - reset send buffer block. Then it said wrong checksum.Then resend 625. What all does this mean?
  • When lines get send to firmware it includes a checksum, so firmware can test if there was a communication error. If there is one it says checksum error and wants host to resend that line, here 625 so it executes the correct command. That is what you have seen here.
  • Okay, so how should I go about fixing the checksum error or the communication timeout?
  • How often does it happen? As I said a few errors happen with some printers. It all depends on usb cable quality, noise from printer to usb or other components, ...  

    What often helps to reduce frequency is using slower speeds like 115200 baud. Would not go further down. Sometimes even switching from 115200 to 250000 reduces it as it has different timings.
  • It happens a lot. What happened was we were trying to start a print and it ended up giving checksum errors. Then the printer stopped but the software continued then it said communication time out. Currently, we are set at 115200 baud rate. So youre saying i should increase my baud rate to 250000?
  • It is worth a try. But you need to change it on firmware and host to make it work!
  • So I tried that and it didn't work. I also tried going slower than 115200 and it didnt work. I keep trying to start the print and it will start to move but then almost immediately freeze. Any other reccomendations? I read somewhere that if you are using windows 10 that it could be the problem
  • Don't see why window 10 should be a problem. Have used it successfully and many others as well. But you need a signed driver or installtion of driver is difficult. But that is no problem since you have a driver.

    Have you tried different and short usb cables? Sometimes the problem is also in usb cable. Have some that create errors while others work good.
  • We have tried a 6" usb cable as opposed to our 3' one. That did not fix the problem. Do you have any other suggestions?
  • Maybe first check what the real problem is. Send
    M111 S24
    to firmware. Then all commands are ignored, but errors will get checked. If there are still many errors I have no more suggestions.

    If that can send a print job without much errors it is just crosstalk from powered wires so you could solve it by better shielding the communication path. Often motor/extruder cable hit usb cable or come near etc and can cause noise resulting in errors. With M111 S24 you do not enable any motors/extruders so all this noise is gone for testing.
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