N0VUSUN and Mitsubishi-D700-SC

[JAZZCNC]

I'll shut-up now, Jazz is giving clear instruction and it helps no-one for me to talk over the top of another.

No don't Doddy you have actual experience with this controller and more experience than me with electronics so your the perfect man to help him. Crack on and I'll just dip in if I see something that gets missed.

Edit: Perfect example I also missed the pulling up not down in the VFD manual which proves "you-the-man" . .

[Daveo]

Nvem S-Axis out1 Orange and White twisted pr goes to STF on the VFD..... through relay
Nvem S-Axis out2 Green and White twisted pr goes to STR on the VFD.......through relay
S-axis /Gnd1 goes to terminal 5 on Vfd which is Analog Gdn
S-axis/VSO goes to terminal 2 on VFD which is 0-10V.

So do i keep the above connections but with the addition of a relay,
i have these relays that came with a box of parts i ordered.

[Daveo]

Hi Doddy
thanks for the reply's i will reply one at a time so i don't get mixed up with the replies

i used the cat 5 as i has several meters laying around and paired the colours together as i found them stronger as single wire broke very easy,i referred them to twisted pairs as that's how they are when stripping the outer cover off, i did not use the cat 5 to reduce EMI and to be honest haven't even thought of that at this stage.
i am still in the testing stage with the electrics but i am 90% done just the spindle VFD and limit switches to do.


thanks Dave

[Daveo]

sorry mate, a diagram would be great,
is it the Mitsubishi VFD that is causing the problem as i sooner change it
thanks Dave

[Doddy]

Quick and dirty schematic:-



First option if the NVEM will source enough current to switch the relay. There's a reason why it might not, and I'll put this on the bottom of this reply, but try that first. The diode is connected across the coil, it's purpose is to protect the NVEM from back emf. I'll let you google the reason for this rather than lying. It's important.




The second option introduces a transistor (any general purpose PNP would do with a VCEO rating of 30V, Ic of 50mA, and a hfe (gain) of at least 100. That describes pretty much any general purpose transistor. I'd guess at a 2N3706 but any similar would do. If the output from the NVEM is switched - it goes low - that will drag the base voltage on the transistor significantly below the emitter voltage (24V) and the transistor will conduct C-E, and the relay will actuate. The current through the NVEM will be in the order of 1mA.


The reason why I'm uncertain if the NVEM will source the current for the relay directly is centred around Lies, Damned-Lies, and Data-Sheets.

The EL3H7 opto-isolators internal to the NVEM are rated at 50mA Ic (collector current). That is, beyond 50mA you risk damaging the transistor. But, the actual Ic is a product of the CTR (Current Transfer Ratio) of the device and the forward current through the LED internal to the device. Typically designed around 10mA, could be 20mA, but the CTR is specified as between 40% and 320%. So, guessing a 20mA current flow through the opto-isolator LED, the actual transistor current will be between 40% (4mA) and 320% (64mA), depending on the manufacturing process. So... 4mA won't switch the relay, whereas 64mA would (though the relay coil resistance would limit this to 36mA).

That's why you'd be best doing a bench-test on the relays first.

[Daveo]

thanks Doddy
so am i just using the out1 on my NVEM an no other connections
Dave

[Doddy]

Sorry, I meant that as means of example of interfacing a digital output from the NVEM to the VFD. That's the control for... STF. Repeat for Out2 and the STR input the VFD (if you think you'll use reverse - you can omit this otherwise). Then the analogue 0-10V output (and ground) is as Jazz said.

[Daveo]

hi
sorry i have to hold my hands up as i am just not getting it,
heres my controller

heres my VFD


I need it in a bit more basic terms so if a diagram with what goes where on the nvem. vfd and relay would be very much appreciated
thanks Dave

[JAZZCNC]

hi
sorry i have to hold my hands up as i am just not getting it,
heres my controlle

I need it in a bit more basic terms so if a diagram with what goes where on the nvem. vfd and relay would be very much appreciated
thanks Dave

This should help, it's basic setup with a diode across the relay to stop back feed from blowing the output up. See Doddy's rough top sketch for diode details.

[Daveo]

Hi jazzcnc
Whats the value of the diode please
thanks

sorry mate,just seen it in your first diagram N4001