Modbus in ClassicLadder doesn´t work

Hey,

I have just Updated to Debian Stretch, the 32bit version.

But now, the Modbus doesn´t work anymore.

The Hardeware seems ok, under Windows I can comunicate with the Hosts.

But in Linuxcnc I get an communication error.

Any suggestions? The USB-Rs485 is listed, when I enter a command prompt with "lsusb"

The same I´ve got when testing the 64bit version of stretch.

Best regards
Marcel

Does the usb port show up as a serial port in /dev ?

Hey,

there show up a file called "ttyusb0", when I plug in the Stick.
Is this the right one?

Had looked in the Internet for solutions and found this:

First I needed to uninstall brltty. This seems to interfere the ttyUSB0.
Then I had to open the console and enter
sudo chmod a+rw /dev/ttyUSB0
then it worked...

Does someone know, what was wrong?

Best regards
Marcel

I have just Updated to Debian Stretch, the 32bit version.

If you did that, you are a long time in the past my friend. 32 and 64 is just factor 2.

brltty is not a common used program or code. Sure not for linuxcnc.

The attached code is a example how to connect modbus to linuxcnc in python, the main script for starting up linuxcnc.
Attached also a hyperterm powermax modbuss connection, provided by the indian.

Hey Grotius,

ok, so I should update to 64 bit?
brltty was already installed with the Image of LinuxCNC, in both versions, the 32bit Image and the 64bit Image. With this installed, I didn´t get the ttyUSB0 in /dev, but after deinstall this, the ttyUSB0 showed up. But don't now why, the brltty seems for people who needs a braille attachment.

Ok, with python I have absolute no experience...
Do you think, with python it is easier to set up modbus in linuxcnc then in classicladder? The only reason I need modbus is for reading out the load on the servo drives...

Best regards
Marcel

MATZE-ATZE-SCH wrote: Had looked in the Internet for solutions and found this:

First I needed to uninstall brltty. This seems to interfere the ttyUSB0.
Then I had to open the console and enter
sudo chmod a+rw /dev/ttyUSB0
then it worked...

Does someone know, what was wrong?

Best regards
Marcel

Yeah, that need read and write permissions while they are normally set to read only.

I think .so / .ko depends on kernel (RTAI) or uspace (preempt-rt) real-time flavour rather than 32/64 bit.

I just documented basic modbus ladder with my RS-485 12V relay channel switch. You might check this page github.com/Hortensie/CNC_x_axis_linuxcnc...er-and-RS-485-Switch