AXBB hookup question

[Greolt]

Can I hookup my THC in the way shown in pic?

The THC outputs a 24v signal (probably 12v in my case)

Prevously I was using Mach3 via LPT with BoB, I used some opto-couplers to get an on/off switch from that voltage signal.

Now I am installing the AXBB in the plasma CNC.

I think this will be OK but wanted to check. Do I need to add a current limiting resistor?

THC is entirely separate from the AXBB power supplies.

Shown is arcOK signal. It will also have UP and DOWN signals.

They all three share a common return on the THC. Can I daisy chain the negative connections on the AXBB?

[dezsoe]

Yes, it's OK. As you can see in the AXBB manual, the inputs are designed for 24V, so you don't need any resistors. The - pins can be common.

[Greolt]

Thank you Dezoe

No doubt I will soon have more questions.

[Greolt]

Could not find this info in the manual.

What current is the isolated input capable of sinking.

Many similar devices I have used in the past have a 20ma limit.

Assuming this can handle more than that.

[Robertspark]

Page 19 and 20 of the axbb manual states the inputs have 2.2k ohm resistors

Ie 24volts/2200 = 10mA approx

[Greolt]

Thanks for the pointer (reminder to RTFM) Rob

Port#1 pins 2. to 8. are isolated outputs. These outputs contain high speed 10Mbit/sec optocouplers and an N-channel Mosfet transistors.
The outputs can drive up to 500mAmps of current up to 24Volts voltage levels.
The high current capability of the output transistors makes these outputs ideal to drive relays, solid state relays and other signals which require isolation.

My relay that draws 38ma should be fine.

[cncdrive]

Yes, there are power mosfet transistors on the outputs. We recommend switching up to 500mA current max. per output. It should be more than enough even for large relays.

[Greolt]

My second AXXB is about to arrive. This one is going in my router.

Most of the hookup is straight forward. Inputs are fine.

However I have five axis to control and only eight non isolated outputs on port 1.

So I am wondering should I control the fifth axis (step and direction) with two isolated outputs on port 1, or pick up two (assume non isolated) outputs on port 3.

These would be connected direct to pins on port 3. I don't have real estate for a BoB just for two extra outputs.

Drives have isolated inputs.

[dezsoe]

If the inputs on your motor driver are optoisolated then you can connect them to port 3.

[Greolt]

Thanks Dezoe

So hooking direct to pins on port 3 should not be a problem.