Mesa 5i25+7i77 plug-n-go configuration

33zy wrote:

attached subject show pin file

File Attachment:

File Name: halcmd_show_pin.txt
File Size:29 KB

That is a list of all the HAL pins that you can use in your HAL configuration.
You can search the pins for likely names, then look at them with Halmeter to see if they do what you require.
Each pin can be connected to other pins by signals. You can see in your list that some pins are already connected to signals, and most are not (which is normal)
Taking a typical line:"7" shows which HAL function the pin belongs to. So, if you find a likely looking pin and want more information, you canfor the list of HAL functions, and you will see that (in this case) function "7" was "motion-controller" and you can (with a bit of inside knowledge, admittedly) then know to go to
www.linuxcnc.org/docs/html/ and scroll to the bottom to where "motion" is and then find this page www.linuxcnc.org/docs/html/man/man9/motion.9.html Or if you are happy in your terminal, just type "man motion"

"float" is the data type of the pin. There are 4 of these, float (real decimal numbers), unsigned and signed 32-bit integer numbers (s32 and u32), and boolean "bit".

The next entry is the pin direction. Any signal can be connected to any number of "IN" pins but only one "OUT" pin. This means that only one pin is allowed to set the value held by a signal and any other pins connected to the signal will be made to have that value. The "OUT" pin sets the value, the "IN" pins read and use the value.

The next entry is the value the pin held at the time you typed the command. You will see that the floats show numbers, the bits show "TRUE" or "FALSE" , the s32 pins show whole numbers, and the u32 pins show gibberish. This is because (for a reason I can't quite fathom) u32 pin values are always reported in this listing in Hexadecimal. You can set them in decimal if you wish, and unless you actively format a number as hex then HAL will read numerical values as base-10.

After the value we see the name of the pin. These are fixed names set by the HAL components. You can only use pin names that exist, and you have to spell them right, which is why having this list to copy and paste from is useful.

Next, on some pins, we see an arrow. "<==" or "==> and after that a signal name. The arrow shows the direction of information flow. In your configuration the signal names were set by pncconf, and look a bit like HAL pin names. However it is important to realise that signal names don't mean anything. You could co through your HAL and randomly change signal names, and as long as they stayed the same everywhere they were used, it would still work. This is a common source of confusion as people see that they have a signal called, for example "x-limit" and see it changing value, and wonder why they have no limit switch function. The reason in that case is that the signal might be connected to a physical input, but is not connected to the pins from motion ("axis.0.neg-lim-sw-in" in this case) that actually does something with the information.

33zy wrote:

Does the 7i77 close the loop on both velocity and position?

You can probably configure it either way, but things are typically easier if you let the drive close the velocity loop and close the position loop in LinuxCNC. (no loop runs in the actual 7i77 or 5i25 in a LinuxCNC configuration)
I have my mill running with dumb (current mode) drives and it is working fine, though.

If I do need this function of the be25a20, then I am in a pickle because the Be25a20 interprets single ended encoders and I installed differential.

I think that is just a matter of wiring. PCW can probably clarify.