Schneider Altivar 320 wiring / setup help needed

[TadasM]

I must say that I don't understand how this is working! The hddb2 board has a constant 12V on the 12V output pins, not controlled by UCCNC. There should not be a problem with the output pins - they do not deliver any power, they are open-drain Mosfet outputs. In effect, an electronic switch with one side connected to ground. The manual shows that these digital output are completely independent of the analogue signals. That's why the VFD is configured to use its internal 24V supply so that you control it by switching the DI inputs to ground. I would not be happy to use this setup as it is now wired because I do not understand how it works at all!

I will make short video this afternoon to show how this is working and what problems I have if output 4 is used (instead of 12Vout). I was surprised my self - but after I just tried and it did worked :D

[TadasM]

It is funny how small, simple thing can get so complicated.
I have tried to demonstrate how things are working, but cant get even run the spindle in one direction - UCCNC software keeps giving message just after start that it was disconnected ....

Disconnected both DI1 and DI2 and than I can start UCCNC... once connected to DI1 for FWD function, after M3 command UCCNC just gives message that UC300 have been disconnected...

Im bit confused now...

Didn't had enough time today to look further, but will do this tomorrow... I will start with only FWD direction this time :D

[Lee Roberts]

UCCNC software keeps giving message just after start that it was disconnected ....

Hiya,

Try swapping the USB cable for another one (keep it short in length, 1m)

If you use the USB port on the left side of the laptop, change to the right side USB port.

Also, make sure "power saving mode" is turned off in your laptop bios.

.Me

[TadasM]

Hi again :)

So finally I got additional information, here is photos showing how spindle is connected:



And here is the video showing the problem:




I have measured voltage between GND and Output 3 - it shows approx +24v when spindle is in "rdy" mode. Once I hit CW rotation in UCCNC voltage drops to 0v and as you can see in the video I receiving message that UC300 have been disconnected.
Should the voltage be 0v at idle and +24v when spindle starts to run ?

Lee, thank you for your advice reg. USB cable. Tried with shorter one - same results. I have added ferrite rings on the both ends of USB cable - no luck either :/

Any thoughts ? :)

[Neale]

I think that I might have found the problem. Altivar installation manual, top of p48. "If using Sink Int do not connect 0V to ground". The manual is not consistent but I think that they use "0V" and "COM" for the same connection. Unfortunately, the HDDB2 has one side of its output connected to ground, so that this connection breaks the Altivar connection rules.

I think that the easiest and safest way to connect the two devices is to use an external relay between the BOB and the VFD. You can then use the Source mode on the VFD, which allows you to connect the analogue ground on the BOB to COM on the VFD (as far as I can see - but I have not read the whole manual!). If you use 12V relays, then you already have 12V available from the BOB. Connect relay coil between 12V and BOB output pin, and connect the relay NO contacts in place of the switches shown in VFD installation manual p48, first diagram. This is an example of the kind of relay that you could use although I do not know what is easily available in your country.

[Lee Roberts]

This is an example of the kind of relay that you could use although I do not know what is easily available in your country.

I've used these pre-built relay module boards for few home projects now with good feedback:

12V 2 Channel Low Level Relay Module OPTO-Isolated Relay Module Expansion Board,

could be a better option over building your own PCB, if you can use one for this.

.Me

[Neale]

Quite a lot of BOBs just seem to have a simple opto-isolator output with floating connections, precisely to stop this kind of ground loop problem. The HDDB has an opto-isolator but then uses it to drive a MOSFET output stage for more switching capability (higher voltage/power than the typical opto-isolator). Clever idea but a bit of a pain in this situation!