Oak drive connector signals

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tblough
Posts: 131
Joined: Tue Mar 22, 2016 10:03 am
Acorn CNC Controller: No
Allin1DC CNC Controller: Yes
Oak CNC controller: Yes
MPU11 & GPIO4D -w/ 3rd Party Drives: Yes
DC3IOB: No
CNC11: Yes
CPU10 or CPU7: No
System Serial Number: 100505
100327
102696
Location: Boston, MA
Contact:

Oak drive connector signals

Post by tblough » Mon Dec 11, 2017 11:33 am

I'm starting to debug the drive connections on my Hardinge lathe conversion and I just wanted to clarify the behavior of a few signals.

If I understand correctly, the Oak will output 24V on pin 21 (enable) when not in estop. The Oak will enter a fault condition when the drive supplies 24V on pin 19 (faultin). The Oak will supply 24V on pin 22 (drive reset) when the oak is in fault condition and estop pressed.

Is this correct?
Cheers,

Tom
Confidence is the feeling you have before you fully understand the situation.

cncsnw
Posts: 350
Joined: Wed Mar 24, 2010 5:48 pm

Re: Oak drive connector signals

Post by cncsnw » Mon Dec 11, 2017 2:24 pm

No. Both the inputs and outputs use "negative logic".

1) Oak will pull the ENABLE signal (pin 21) down to 0VDC when the drive should be enabled. Oak expects the drive to have an internal pull-up resistor to +24VDC (pin 23) which holds the ENABLE signal high (not enabled) whenever Oak is not actively pulling it down.

Note that, on Centroid controls, drives are not automatically enabled just because E-stop is released. Drives are only enabled on demand: either when you press a jog key for that axis, or you move the axis with an electronic handwheel, or you start a program cycle. Once enabled by one of those actions, the drive remains enabled thereafter until a Fault condition (such as E-stop) or Stall occurs, or you explicitly remove power with an M93 code or Aux key function 14.

2) Oak expects the drive to pull the FAULT IN signal (pin 19) down to 0VDC when all is okay. Oak has an internal pull-up resistor to +24VDC which holds the FAULT IN signal high (drive fault) when the drive is not actively pulling it down.

Note that "FAULT IN" really is "NOT-FAULT IN". It is expected to be active (pulled low) when there is no fault.

3) DRIVE RESET (pin 22) works the same way as ENABLE.

If your servo drives require positive logic (e.g. expecting you to apply +24VDC to enable), then you will need to insert relays in between the Oak and the drive to switch signal polarity.

tblough
Posts: 131
Joined: Tue Mar 22, 2016 10:03 am
Acorn CNC Controller: No
Allin1DC CNC Controller: Yes
Oak CNC controller: Yes
MPU11 & GPIO4D -w/ 3rd Party Drives: Yes
DC3IOB: No
CNC11: Yes
CPU10 or CPU7: No
System Serial Number: 100505
100327
102696
Location: Boston, MA
Contact:

Re: Oak drive connector signals

Post by tblough » Mon Dec 11, 2017 10:15 pm

CNCSNW - sorry to keep bothering you but before I remake my cables, I just wanted a sanity check.

This is the drive enable circuit of my ABB drive:
Enable.png
Based on your description, I should be able to connect [Drive Enable+] to +24VDC on the OAK's drive connector. [Drive Enable-] would then connect to the OAK's drive enable pin. When the Oak pulls enable low, opto lights up enabling the drive.

The Oak's fault input will be handled by the drives Status Output:
Status.png
The drive's [Status+] would connect to the Oak's fault input. The drive's [Status-] would connect to 24 GND on the Oak's drive connector.
The status output on the drive is configurable and assuming the [Error] signal on the diagram means an error exists, it looks like it should be set to active high. So, no error would have [Error] pulled low lighting the opto LED, output transistor conducts, pulling the Oak input to ground signalling "good" status and therefore "no fault".

Finally the fault reset is handled by the drive's configurable digital input:
DI.png
Drive's [DIN0+] goes to +24V on the Oak Drive connector. Drive's [DIN0-] goes to Drive Reset on the Oak's drive connector. If the drive needs to be reset, the Oak pulls Drive Reset low lighting the opto, causing the input transistor in the drive to conduct pulling the input to ground. Therefore the digital input on the drive should be configured as Active Low.

Does that logic make sense?

Tom
Cheers,

Tom
Confidence is the feeling you have before you fully understand the situation.

cncsnw
Posts: 350
Joined: Wed Mar 24, 2010 5:48 pm

Re: Oak drive connector signals

Post by cncsnw » Tue Dec 12, 2017 11:36 pm

Those connections sound like they should work.

tblough
Posts: 131
Joined: Tue Mar 22, 2016 10:03 am
Acorn CNC Controller: No
Allin1DC CNC Controller: Yes
Oak CNC controller: Yes
MPU11 & GPIO4D -w/ 3rd Party Drives: Yes
DC3IOB: No
CNC11: Yes
CPU10 or CPU7: No
System Serial Number: 100505
100327
102696
Location: Boston, MA
Contact:

Re: Oak drive connector signals

Post by tblough » Wed Dec 13, 2017 4:10 pm

Well, looks like this is turning out to be a drive configuration problem. The wiring scheme in this thread matches what I had developed more or less independently in a previous thread ABB Microflex Servo and OAK connections. Encoder connections are working correctly so I'm positive it not a question of reading the pin positions wrong on either the OAK drive connector or the MicroFlex connectors.

Here's to more debugging this weekend.
Cheers,

Tom
Confidence is the feeling you have before you fully understand the situation.

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