Wizard PLC function to change spindle direction and enable?

[friolator]

I need to send 5-24V signals to the Direction and Enable pins on a Teknic Clearpath motor. Looking at the wizard, the only thing I can find that looks right is VFDDirection and VFDEnable. I don't have a VFD but this seems like the functional equivalent. If I assign VFDEnable to an output in the wizard, it seems it activates the corresponding relay on the relay board.

I'm a little confused about the relationship between the DB25 outputs and the relay outputs. According to this PDF, Outputs 1-4 have two "Output Locations" - the relay board and the DB25 connector. When I set VFDEnable to one of these 4 and I tell Acorn to spin the spindle, I hear one of the relays get triggered. So does that mean that it does both simultaneously, or it does one or the other?

I think a 5V signal from the DB25 should do what I want, but is it possible to have it work without also triggering the corresponding relay for that output?

[suntravel]

VFD enable triggers the Output# it is assigned to in the Wizard, no matter If you use DB25 or the relayboard.

Since it is not time critical, I use the relay board for the ease of wiring.

Uwe

[friolator]

so then Outputs 1-4 (relays) and DB25 pins 1, 14, 16, 17 are always linked together? It seems to be this way, testing with a voltage tester.

I wired up the enable and direction pins to the DB25 breakout, but the behavior is the opposite of what I'd expect: The Teknic motor is coming up enabled by default, and when I tell Acorn to start spinning the motor, it disengages (confirmed in the Teknic software and via voltage readings on that Acorn output pin).

Is there a way to invert the behavior on the Acorn side so VFDEnabled is disabled by default?

[centroid467]

There's two paths that I can see:
1. Wire to the output relays and choose the NO or NC contact depending on whether or not the enable input needs to conduct to be on.
2. Find the line in the PLC and invert the behavior.

[cnckeith]

There's two paths that I can see:
1. Wire to the output relays and choose the NO or NC contact depending on whether or not the enable input needs to conduct to be on.
2. Find the line in the PLC and invert the behavior.

#1 is the easiest, suggesting a plc program change and compile is fraught with danger.

[suntravel]

No Risk No Fun

But I would always choose a way if possible without editing PLC, makes updates faster.

VFD Direction and VFD Enable is perfect for a servo driven spindle on the relayboard since you can easy wire it to NC or NO.

Uwe

[friolator]

I agree with not wanting to deal with the PLC stuff right now, especially since I'm still coming up to speed on Acorn as a whole. However, the wiring was cut to fit the distance to the Acorn board, not the relay board, so this poses some challenges. I may be able to flip the relay board so the relays are on the right side instead of the left, and eke out a couple more inches of wire to get it to reach. If not I'm looking at splicing in some extensions on the wire, which I'd like to avoid.

A quick question: Is there any issue with using the relay to switch on and off the output of the matching pin on the DB25 breakout? That is:

DB25 PIN 4 Outputs the Enable signal for the motor, and I wire that into the NO terminals of the relay, so the relay effectively turns that on and off. I don't see an issue with that since the signal being switched by the relay is isolated from the circuitry on the board itself, but figured I should check first.

[suntravel]

Outputs on the CNC are not switched by an relay, they are switched with the software and can switch an relay.

You like to make simple things complicate...

Uwe

[friolator]

I just pulled 24V from the acorn into the relay NO terminal and I'm feeding that to the motor. It's all up and running now. Had to rejigger a bunch of my wiring to get it to reach the relay board but it's working:



Yes, I'm aware of how bad that pulley is. But without a lathe I had to drill that hole larger to fit the spindle shaft -- on my drill press. So it's not concentric. First job on the lathe will be to bore a new pulley to the correct dimensions.

[friolator]

Outputs on the CNC are not switched by an relay, they are switched with the software and can switch an relay.

You like to make simple things complicate...

It's not about making things complicated - I didn't think I had enough wire to the motor (which has a custom cable I had cut short to reach the Acorn board. I was trying to figure out a way to do it with what I had to work with.

The DB25 pins output 5VDC when turned on by the software so my thought was to have those be the input voltage to the relay, then when the relay closes, that 5V goes to the motor. But after looking at the layout in my control box again, it was actually easier to feed the relay's input 24V, and then have it switch that to the motor (since the motor can take 5-24V either way should work).