Advanced Search

Hello,
I'm helping some friends to use a 7i73 connected to 7i96s for a CNC.
7i73 is using Firmware 14 (read from linuxcnc) with a custom adapter board to make it easier to connect a panel with switches and mpg. 7i73 is in 4x8 mode with analog in and no lcd (jumpers set accordingly & sserial=10000...).
The adapter board doesn't do much besides adapting from IDC Connectors to screw terminals.
In general the system works fine and the keypad also works with linuxcnc - buuuut all keys connected to KEY8(in) don't work. Other keypad-switches are working fine.
Cabling was done with 0,5mm² and it is quite a mess. My first guess was the big and long cables would have too much capacitance and the 10k pullups couldn't pull the line back up in time.
Bridging with a short cable made it work, so card and general set-up seems to be ok.
Replacing the 10k pullup resistors with 1k did NOT do the trick!
After some Scope measurements it actually looks like the KEY8 inputs will be measured far to soon after enabling e.g. the KEY4 output line. The outputs will be (open drain) low for ~30µs. In the scope the difference in the signals will be very little and only in the first few µs.
So the conclusion is that the KEY8 inputs will be sampled early after setting the row outputs. With my long cables and many connections it looks like this will make it unreliable to get the right switch input.
Shorter cabling is not really an option. And in case the signals are really sampled that early I'd rather like to somehow get that fixed in the firmware.
I counter-checked with another 7i73 board from another batch and did see the same result.

Attached pictures show the testing setup. Scope screenshots are from the video:
Scope cabling is not much better than the key cabling but it should still show the most important...
Yellow is KEY4 (open drain output with added pullup to see measurement moment without button pressed).
Blue is KEY8 input with pullup (not sure if original 10k or already changed to 1k).
The video is showing the difference of:
- a bad signal, "shorted" via switch that will not be seen in linuxcnc meter
- a "good" signal seen in linuxcnc meter, done by bridged signals on adapter board (very end of video)

Can anybody confirm this?
Could it be a problem in Firmware V14 that only KEY8 is sampled early?
What would be the solution for this problem?

Thanks for your help!
Alex

found the problem
I see it is talking about missing raspi-firmware.
to remove enter the terminal
then enter
sudo dpkg -P raspi-firmware
now the error is gone.
 

The 7I84 needs VFIELDA VFIELDB and VIN

Suggested wiring is to power VFIELDA and VFIELDB and leave W1 in the default
left hand position, so VIN get powered via VFIELDB.

He,

I have a 7i84 connected to a 7i77. Lcnc can see the device but the red is always on and I am not able to control the outputs. Could it because I only have 24v connected to vin. Does the field a and b niet power?


Thanks 
 

  So I decided to do a fresh install on the computers for my Mill and Lathe. The computers areDell Optiplex 9020 micros. I am installing Linuxcnc V2.9.4 ISO. After installing and then updatingI get an error message ofE: Subprocess /usr/bin/dpkg returned an error code (1)it also says there is an issue with initramfs-tools.all that said I am attaching a pic of the error message to help. I am sure I am missing something stupidI usually do. LOL
   
 

Did you try pinning the Ethernet IRQ to the last processor?

This usually make a large difference in Network latency

Yes, correct!
But I’m still having some issues with the config upload, which I’m currently investigating on the EC500 board.
If you're unable to change the config, you may need to erase the entire chip first:

Then flash the firmware again and upload the new config.

This worked for me, but it's definitely not an ideal solution...