5i25 - 7i76 support testers wanted

yes there is no sanity test for the 7i76. just uncheck the default 7i33.

Ok so I have everything connected and powered up. Went trough Pnpconf to get a basic configuration (see attached files).

Now i can start LinuxCNC select my configuration, the program starts, no error messages showing but I cannot remove the EStop ??!!

It must be some really silly thing but i cannot figure it out. Any suggestions ?

Regards

JBlain

Oups the attachement didn't make it. here it is

yes it looks like you picked the classicladder external estop option. yes?
This requires an external input to come out of estop.
It may even do this if you select an estop input (as you did)

Either connect the physical estop signal or start PNCconf again and remove that option.

Ok it took me a while to come back, I was busy with other stuff...

Sooo, as I was advised, I jumped the pin I had defined as an external estop and LinuxCNC became much more cooperative. But I am still stumped about making my motors actually step. Here is were i am :

I know the mesa 5i25 driver is installed and working because my external ESTOP defined trough PNPConf works.

But getting motor steps and dir signals out of the 7I76 board doesn't work ??

My understanding is that on the 7I76 TB2 connector

PIN 1 is ground
PIN 6 is 5 V

My scope is showing this as correct, so far so good

PIN 2 is STEP0- showing as logic low 0.2 Volts
PIN 3 is STEP0+ showing as logic HIGH 5.0 Volts
PIN 4 IS DIR- showing as logic low 0.2 Volts
PIN 5 IS DIR+ showing as logic high 5.0 Volts

In PNPConf I see I/O connectors 2 and 3 tabs which I understand to be TB2 and TB3 connector tabs

If I go to I/O connector tab 2, I do not see pins numbered from 1 to 24. Instead I see numbered pull down lists that I have setup up as follows

5 X Axis StepGen
6 Y Axis StepGen
7 Z Axis StepGen
8 A Axis StepGen
9 Unused Stepgen
2 Is disabled in PNPConf
3 Unused Channel
1 Unused encoder

So I am guessing that PullDown list 5 refers to the 1..6 pin group which will control the X Axis ?

So then :

1) I save my configuration (see attachment configuration UppercutMesa)
2) I start LinuxCNC
3) Remove the software ESTOP (in the current config I have no external ESTOP)
4) Toggle Machine Power
5) Connect my scope between Pin 1 (ground)
and pins 2, 3, 4, or 5
6) Then I press the + or - manual button for axis X

Altough I see the X position changing on the display, I never see any level changes on any of the pins I monitor

So what am I doing wrong here ?

Regards

J Blain

Its a very weird setup to skip the first connector, not only is this likely to trigger pncconf corner conditions
it also is very suboptimal as far as pin use and CPU time goes

I would try an standard config first

That is to say if you are using 4 stepgens they should be stepgen 0, 1, 2, and 3, not 5,6,7 and 8
(which on the standard 7I76x2 config are on the second 7I76 connected to P2 not the normal external P3)

I also note that the 7i76 inputs in the hal file are on sserial channel 0 (on P3)
so if they work, stepgens 5,6,7,8,9 cannot work because they are unconnected (they are on header P2)

The numbers beside the drop down list are the component number (or HAL pin number) not the actual physical pin number.
so you have
axis x using stepgen # 5
axis y using stepgen # 6
axis z using stepgen # 7
etc
You must look in the MESA manual for the 7i76 to figure out what actual pin number that is or
if you added the pin description file as well as the XML description file then while on the Mesa configuration page press the help button
and look at the output page - it is copied from the manual to help you convert component number to actual pin number.


PNCconf tells you that they are on connector 2 and 3 (they are) but that is referring to the 5i25 main board.
The 7i76 daughter board redirects these to its own connectors.
And it just so happens the first stepgen (component 0) is actually on connector 3 not 2- not intuitive.
This is a function of the firmware.

Its the same for the sserial I/O pins - the numbers refer to the component number.
Get the component number and look up the actual pin number.


I should add some clarification to the help page.
Chris M

oops i see I wrote the XML file wrong and the P2 and P3 connector numbering is backwards.
It doesn't hurt anything other then it's labelled wrong - its the component number that is important.

I'll fix it soon...
Chris M

And it just so happens the first stepgen (component 0) is actually on connector 3 not 2- not intuitive.

Well it really cannot be, the reference designators are done by physical board position and are just that, for reference

P3 is the external DB25 connector and usually has the first of everything since most systems dont even need the second (header P2) connector

Pinout questions such as which stepgen get routed to which 5I25 connector are easily resolved by looking at the .pin files that
accompany the bit files

My point about starting at 0 with hardware modules is quite important. Basically you do not want to start using
encoders, stepgens, pwmgens etc at any number other than 0 for at least a couple of reasons:

1. The way the driver allocates pins means that the unused outputs of stepgens, PWMgens etc are wasted and cannot be reclaimed as GPIO
2.Unused hardware will still use CPU time in the driver for I/O access and processing that is totally wasted.