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Thanks Scott, this was my one predicted hurdle when I started research months ago. Glad to be alongside another on this project.

At idle, counts remains unchanged unless I physically touch the nozzle, and then it will increase. I’ll have to check halcmd outputs tomorrow and I’ll post.

Yeah, I’ve wondered about the counter rate. I have a 7i76e with a 7i85s. This was originally plugged into the 7i85s but I read in the manual the encoders are muxed to save pins which limits count rate to 2-3 MHz. I’ve since plugged it into the 7i76e encoder spot.

Great to hear you having success. Are you finding any limitations with the low sensor range with things such as tip ups? A lot of the Chinese systems I’ve seen can track 6mm and more sense distance. Perhaps it’s not using this amplifier.

I have a Raycus 1000w with a Raytools BM110 auto focus head.

@PCW encoder filter is set to 0. Will try increasing sample rate and report back. 

Looks like you've nearly got it working. I'm not at the machine right now, but "idle" away from any metal it reads a fairly high and constant velocity. I wonder if you are having encoder counting issues in software. The signal looks plenty clean to be counted properly. Since you do have:

counter-mode 1
filter 0

for your encoder, I'd check via halmeter to see if your encoder counts are constantly going up at idle. They should be in my experience. I'd also double check via halmeter or "halcmd show all" at a command prompt that the counter-mode and filter are getting set the way you think they are for your encoder.

One difference between your setup and mine is that I wired the encoder straight to the Mesa Anything IO board (originally a 5i25 then a 7I92TF). Even then I had to set the "filter 0" to get the performance fast enough. From the manual, the 7i76e encoder looks plenty fast (a count rate of 10MHz). So that seems fine.

If you want to run "halcmd show all" a couple of times waiting at least a few seconds between executions it'd be interesting to see what the encoder is doing. Something like:

halcmd show all > run-1.txt
halcmd show all > run-2.txt

and then share the run-1.txt and run-2.txt files here.

Thanks, and glad to have someone else getting a fiber laser going with LinuxCNC! We've started to tune ours in and cut real parts. What laser source are you planning to use?

Scott

Thanks for detailing this, this is very helpful as I am on my own way to converting my plasma table over to fiber laser.

I've wired up my BCL-AMP as you've described, +5v on pin 1, Signal Out on pin 2, GND on pin 3. For pin 4, I've let that just be unconnected for now; should this connect to something? I was thinking since it's already connected in the BCL-AMP that I wouldn't want to connect the connector end to ground as well as that could create a ground loop. 

My signal (pin 2) goes into pin 1A (input) of a TC74HC14APF Schmitt Trigger similar to yours. I've tied all other inputs on the trigger to GND per the datasheet and supplied +5V from the mesa 7i76e encoder header. The output (1Y) of the trigger goes to the encoder A input, with the card set in TTL mode. My HAL is set up with counter-mode = 1 and filter = 0.

With an oscilloscope probe on the output pin of the schmitt trigger and gnd connected, I can view the frequency response of the sensor. Mine has a no-sense value of about 2.33 MHz. It responds by decreasing frequency when I touch it, or move a metallic object nearby. The schmitt trigger does clean up the signal, but I still wouldn't call it a clean square wave. One thing to note is that I did disconnect the BCL-AMP and put some capacitors inside the connector to do my own bench testing. The output signal on the scope is very stable (frequency wise) with a constant capacitance.

I'm having issues in linuxcnc getting a stable reading from the encoder velocity's signal. Viewing the velocity signal with the scope, there is 0 value when it is idle (nothing nearby) and it bounces all around whenever I touch it. I also basically have to be touching it to get a response on the velocity signal. I would say it's not even as sensitive as yours (~0.100"). If I sit a piece of metal within the detection range, the velocity value is 0 unless its touching. I'm sure it's noise driven, just can't seem to find it.

What does your velocity signal read when the sensor is idle and not near anything?

 
 

The physical switch input signals names (home-x and both-x):

#--- HOME-X ---
net home-x <=> hm2_7i76e.0.7i76.0.0.input-05
net both-x <=> hm2_7i76e.0.7i76.0.0.input-04

do not match the names (or functions) connected to LinuxCNC's motion component:

# ---setup home / limit switch signals---

net x-home-sw => joint.0.home-sw-in
net x-neg-limit => joint.0.neg-lim-sw-in
net x-pos-limit => joint.0.pos-lim-sw-in

This is true for all joints.

[url=https://www.facebook.com/groups/465128047350433/user/1186219141/?__cft__[0]=AZXp2iAvjPKVttWtEo_h-9s-ccv4qEPy6k0ub7zQ0ht-JGnU3HYOsg79OvJq67HNRT6-DUJ59gB9r1Zj5rZiXV_56ofNC1C82eUB0EDDl3ndsKjJ_Tp5gudk1G1rNiIKNMmi-e_liDLK-Z-ZlLnL-0ew&__tn__=-]K-R]Hello[/url] Im trying to setup a new pc on a existing machine with 7i76e. The output singals for the spindle and the Zaxis brake are working properly .The input singals for the limit switch are not working.What m i missing here? Following the ini and hal files   

Sinking or sourcing only applies to the 12/24V digital outputs
on the 7I76/7I76EU/ It likely makes no difference in your setup at all.

Hello, The more I read the more confused I get so I will seek for help here.

I want to build a cnc mill that is 3 axis for now (would like the option to move to a 4 axis in the future)  I would also like to set the spindle speed via gcode (mitsubishi servo)

I currently have a
2x ClearPath CPM-SDSK-3421S-RLN
1x ClearPath CPM-SDSK-3432S-RLN
1x ClearPath Brake 24v MPC034-24-003-T
3x ipc5 power supplies and all the power/data cables
1x Intel NUC Core i5-9300H, 16GB RAM, 512GB PCIe SSD

Is the 7I76 cards what I need to make this work or is there a better one?
If so can you please tell me the difference between the 7I76E (sourcing output) and 7I76EU (universal output)?

Any hints on where to find a 7i76e (or 7i76eu) now? Both Eusurplus and Welectron are out of stock, plus I've been looking for one on local ads and Ebay for a year with zero success.

Promo wrote:

Hi all,

Currently I'm trying to convert a BF30 to CNC using a 7i76e and linuxCNC with Probe basic.
During testing I would like to override the soft limits such that I can move the axis outside machine coordinates.
Probe basic has a 'override limits' option in the 'machine' dropdown menu but I can't select it. It acts if the button is greyed-out.
Do you know how I can activate the override limits function? Or is there a different way to move the motors outside of the machine-coordinates?

It might be a very silly question but it is all quite new to me.

Thanks for all the help
 

This issue seems to still be there. I can't select the override option either.

Noticed this while setting up my limit switches yesterday. My workaround for now is to fire up Axis as the override option works there.

I'll create an issue on the Probe Basic GitHub page and see if any of the developers chime in.

Cia402 is definitely the way to go.You can follow my basic cia402 example for the Rtelligent ECT60/86 drives. github.com/rodw-au/linuxcnc-cia402
Note that there are two xml files that include a config for a Rtelligent I/O module and another cheaper and more basic deiwu I/O module.
I like the Rtelligent as they are well documented for a Chinese drive and now include servos in their range (Which I have not played with). Another drive we played with only had a couople of registers but we got it moving.
The Deiwu I/O one was built based on output from the ethercat pdos command.

Note that for ethercat, you have to build your config in a text editor as there is no config tool. Having a basic config like I have shared gives you the framework. There was a time when there was no support in pncconf for a lot of cards (like the 7i76e  I started with)

 

I am using a Dell AIO PC OptiPlex 3050 and it has a
Realtek RTL8111HSD-CG Ethernet LAN 10/100/1000M on system board for connection to the Mesa 7i76e
I worked well with the Bulleye's version of LinuxCNC before I switched to 19.4.

Just when I was about to give up and just risk working with the swapped servos, the second servo now shows the same symptoms when running on the bad channel .

So it looks like it is the 7i76e that broke and not the servos .

Plus, that card seems to be still not in stock anywhere in the EU. Already had that problem when searching for one two years ago.

At least I am only using 4 of the 5 channels, so was able to reconfigure the machine the unused channel instead, hopefully I'll find a new card, soon.

Thanks a lot for all your help, PCW!

No 5V driver can supply 5V to a load (it will always have some internal resistance)
You might check the drive input resistance between STEP+ and STEP-
when unconnected. If both drives match then its likely that 7I76E S/D
outputs have been damaged.

Note, when checking the S/D outputs, its  much better to measure both
the STEP+ and STEP-  pins individually relative to ground

Did you swap the motor connections at the 7I76E or the motor?

If differential signalling is used and you have either:

A bad cable
A bad 7I76E step output
A bad motor driver step input

You can get flaky behavior if just one on the differential
signals is working.

I get it! Its a big machine so you do need wireless. But you should not consider  USB.
I would look at this pendant which has a 433 Mhz receiver and designed for industrial use. Pair it with an external antenna at the receiver end.
www.wixhc.cn/product/433mhz-manual-pulse-generator
Unfortunately, you still end up with those 20 odd wires but they are contained in the control box.
These work really well with a Mesa card that has  a MPG input built in (eg 7i76e etc). For Ethercat, you would need an encoder input which are pretty costly. Note the Estop is  dual circuit so designed to work with a safety relay.
There is a fair bit of custom hal code to get these going.

Note Ethercat adds an additional layer of complexity to a linuxcnc build and it was hard work when I built my machine. But it is a lot eaiser today with efforts from myself, Scott Laird and others...