Servo On - Acorn outputs

[osrix25]

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I am setting up a lathe, with Servo spindle and having some trouble with outputs on the acorn. Im sure its my lack of understanding so hoped someone could help.

Links to motor and driver manuals
Lichuan B2 driver and 90 series 3000rpm ac servo
http://servo.xlichuan.com/Private/Produ ... ec943a.pdf
http://servo.xlichuan.com/Private/Produ ... a36fed.pdf



The servo driver Manual shows this

And in more detail

Acorn schematics example of the output

Do I need a pull up resistor on this? there is not one shown in any of the acorn schemes so ive assumed I dont need one.
I was hoping I wouldnt need to use a relay as the Servo drawing seems to suggest the same as the Acorn Scheme . I could of course use a physical switch or put it through one of the relays but how then do I control the relays within the Virtual Control screen?


thanks

Ben

[Richards]

The coil in the relay has one end connected to +24VDC. The other end is connected to an Acorn output pin. The Diode across the coil has the anode end (stripe) connected to 24VDC and the cathode end (non-stripe) connected to the Acorn output pin. The purpose of the diode is to suppress a voltage spike when the relay is turned off. The coil acts as a "pull up resistor". It limits the amount of current that can flow through the circuit. Be sure than you use relays that are suited to the Acorn; i.e., use the relay board sold by Centroid or a board recommended by Marty or Gary. The Acorn technical specs list typical output current as 10mA and maximum current as 50mA. By assigning an output to any of the listed functions in Wizard, when you activate that function (clamp, mist, flood, etc.), the relay will turn on.

[osrix25]

Thanks for your reply, I actually meant the 2 relays on the board, I realise the outputs are assigned to the radio buttons.

[martyscncgarage]

Please review this post:
viewtopic.php?f=60&t=1043

More information would be helpful, make and model of the spindle drive and motor. Link to a manual of the drive and pictures.

[Richards]

Okay, I didn't understand the question. Let me try again.

The top image shows that the internal electronics consist of eight opto-couplers. Each opto-coupler has a current limiting resistor in series with its associated diode. The cathode end of the diode is connected to the external connection point for your interface, for example: pins 5, 6, 7, etc. Your external circuit must complete the circuit for each opto-coupler (that you will be using). Your external circuit must have a GROUND in common with the circuit shown in the top image. If you used a relay contact that closed the circuit when the relay was on, then current would flow from 24VDC, through the current limiting resistor, through the diode, through the contact points on your relay to common ground. That would make a complete electrical circuit, then whatever was connected to the opto-coupler's transistor inside the internal electronics would turn on.

Image two shows two ways to complete the circuit. The left side shows how you could use contacts on a relay to close the circuit. The right side shows how a PLC uses a SINKING NPN transistor to do the same thing.

The bottom image shows how you could use the two built-in relays on the Acorn board. Connect K1-com and/or K2-com to GROUND. Connect K1-Out and/or K2-Out to an external connection pin, i.e., pins 5,6,7, etc. When the Acorn's relay is turned on, the opto-coupler inside your device will also be turned on, which will turn on whatever device is connected to the internal transistor.

[osrix25]

Please review this post:
viewtopic.php?f=60&t=1043

More information would be helpful, make and model of the spindle drive and motor. Link to a manual of the drive and pictures.

Marty my apologies, I have just read this after posting .

[osrix25]

Okay, I didn't understand the question. Let me try again.

The top image shows that the internal electronics consist of eight opto-couplers. Each opto-coupler has a current limiting resistor in series with its associated diode. The cathode end of the diode is connected to the external connection point for your interface, for example: pins 5, 6, 7, etc. Your external circuit must complete the circuit for each opto-coupler (that you will be using). Your external circuit must have a GROUND in common with the circuit shown in the top image. If you used a relay contact that closed the circuit when the relay was on, then current would flow from 24VDC, through the current limiting resistor, through the diode, through the contact points on your relay to common ground. That would make a complete electrical circuit, then whatever was connected to the opto-coupler's transistor inside the internal electronics would turn on.

Image two shows two ways to complete the circuit. The left side shows how you could use contacts on a relay to close the circuit. The right side shows how a PLC uses a SINKING NPN transistor to do the same thing.

The bottom image shows how you could use the two built-in relays on the Acorn board. Connect K1-com and/or K2-com to GROUND. Connect K1-Out and/or K2-Out to an external connection pin, i.e., pins 5,6,7, etc. When the Acorn's relay is turned on, the opto-coupler inside your device will also be turned on, which will turn on whatever device is connected to the internal transistor.

Thanks Richard. Thats very helpful.

Ive actually got the servo On to work using the normal outputs without a relay. using the the mist button. Im going to update the OP with the information Marty has requested, just to make certain what ive done isnt going to damage the board long term.

The new relay board would certainly make life much simpler, I'll have to see if I can get one.