Prox Switch Help [Resolved]

[MSimeone]

Hello all,
I am in the process of retrofitting an older AXYZ router to Acorn (new Acorn control, Clearpath, new spindle, some mechanical changes to machine as well), and everything has thus far been going swimmingly - so much helpful knowledge between this forum and YouTube, etc. However, I seem to be having some trouble with the prox switches. The old switches were PNP, so I purchased some new NPN NC switches from Amazon that fit the factory locations:
https://www.amazon.com/dp/B091CXNVWQ?ps ... ct_details
For testing, I installed one switch. I set the Acorn input to "LimitAll". However, when I trip the switch, the Acorn input does not activate. I can read the voltage change (24V) on the multimeter, so I know the switch is changing it's state. I tried changing the function of the input from NO to NC and back again. The only difference is a constant "Limit Tripped" message, but no change in state when jogged (manually, not via the servos) on or off the limit. Again, switch change in state verified by multimeter. It's like the Acorn input isn't 'seeing' anything.
Don't know how much value is in a report for this, but here it is.
I greatly appreciate any help with this. Thank you,
Mike

[martyscncgarage]

Wire the switch directly to Acorn and test it.
Seems to me the AXYZ routers had some circuit boards and wiring in between the sensors and the control cabinet

[hennessey]

This is the diagram i used when wiring my npn nc (3 wire) sensors i snagged on automation overstock.

Something to note if your machine is wired up in this fashion, unless the x y and z master (which are all wired in series to 1 input on acorn) are *all* plugged in, the circuit will be open (because a missing sensor in the series chain.... breaks the circuit).

[MSimeone]

Wire the switch directly to Acorn and test it.
Seems to me the AXYZ routers had some circuit boards and wiring in between the sensors and the control cabinet

Hi Marty,
Love your videos, they've been super helpful.
That's what I did, wired the sensor directly to the board. You're absolutely right, the AXYZ machines used a bunch of sub boards etc..., all of which have been removed for a fresh install.
Thanks,
Mike

[MSimeone]

This is the diagram i used when wiring my npn nc (3 wire) sensors i snagged on automation overstock.

Something to note if your machine is wired up in this fashion, unless the x y and z master (which are all wired in series to 1 input on acorn) are *all* plugged in, the circuit will be open (because a missing sensor in the series chain.... breaks the circuit).

Thanks! The results are indeed from using just one switch, to avoid this exact situation.

[martyscncgarage]

Wire the switch directly to Acorn and test it.
Seems to me the AXYZ routers had some circuit boards and wiring in between the sensors and the control cabinet

Hi Marty,
Love your videos, they've been super helpful.
That's what I did, wired the sensor directly to the board. You're absolutely right, the AXYZ machines used a bunch of sub boards etc..., all of which have been removed for a fresh install.
Thanks,
Mike

So wiring the sensor directly to Acorn, does it ground the Acorn input or not?
Please post the wiring diagram of the sensor itself.
Glad the videos keep helping folks!
I'm still lurking, just busy and laying low for awhile.

Marty

[MSimeone]

Wire the switch directly to Acorn and test it.
Seems to me the AXYZ routers had some circuit boards and wiring in between the sensors and the control cabinet

Hi Marty,
Love your videos, they've been super helpful.
That's what I did, wired the sensor directly to the board. You're absolutely right, the AXYZ machines used a bunch of sub boards etc..., all of which have been removed for a fresh install.
Thanks,
Mike

So wiring the sensor directly to Acorn, does it ground the Acorn input or not?
Please post the wiring diagram of the sensor itself.
Glad the videos keep helping folks!
I'm still lurking, just busy and laying low for awhile.

Marty

As far as wiring, I just followed the standard 3 wire NPN of:
BRN = +24V (from a 24V power supply)
BLU = 0V/COM (from a 24V power supply)
BLK = SIG (to Acorn input)

I will verify tomorrow that it indeed shows ground on the BLK wire when tripped (and not +24V). Although I can't remember off hand right now which it is, I do know that it did indeed change state when tripped, but that change in state solicited no response from the Acorn input.

[martyscncgarage]

You may have a defective sensor otherwise

[MSimeone]

You may have a defective sensor otherwise

Ill report back tomorrow morning once I get to the shop. I did have a thought - I am going to try using the 0V/COM directly from the connector on the Acorn board and see what happens. As I am thinking about it, the power supply for the Acorn jumpers the COM to earth. The power supply I am using to provide +24V and 0V to the prox sensors currently does not (at least I didn't do it externally, no idea if it does it internally). I can't help but wonder if that may be part of the issue? That power supply is a fairly high quality Weidmuller unit and it does provide proper power to release the Z axis motor brake via an Acorn output (i.e. the motor brake does function as expected via the Acorn PLC).

[martyscncgarage]

You may have a defective sensor otherwise

Ill report back tomorrow morning once I get to the shop. I did have a thought - I am going to try using the 0V/COM directly from the connector on the Acorn board and see what happens. As I am thinking about it, the power supply for the Acorn jumpers the COM to earth. The power supply I am using to provide +24V and 0V to the prox sensors currently does not (at least I didn't do it externally, no idea if it does it internally). I can't help but wonder if that may be part of the issue? That power supply is a fairly high quality Weidmuller unit and it does provide proper power to release the Z axis motor brake via an Acorn output (i.e. the motor brake does function as expected via the Acorn PLC).

It is ok to use the Acorn power supply for the PROX sensors. If you are using a separate power supply for the sensors, then you must connect the 24v common from the power supply feeding the sensors to the Acorn common power supply. Otherwise it can not ground the Acorn input