Machsupport Forum
Third party software and hardware support forums. => PoKeys => Topic started by: hanermo on March 23, 2015, 06:58:16 AM
-
Pokeys 57E+cncaddon.
Servo driver MCA808, with differential signals.
DIR+, PUL+ connected to +5V.
DIR- to pin 3.
STEP- to pin 5.
Servo locks on turn ok-ok.
Jogging works in one direction only.
I tried changing to new plug on the cncaddon board, from 0 to 1.
-Same problem
I tried changing to new servo driver.
-Same problem
Attached the exported xml for pokeys pin settings and pulse engine settings.
Any ideas from anyone ?
Fwiw..
Differential steppers 2M542 drivers work fine, with steppers, on another Pokeys56U.
Differential servo drivers MCA808 work fine on this one, as well.
I need the speed of the cncaddon, though.
-
Can you give some more information on MCA808 drivers? The link to the manual?
PoKeysCNCaddon outputs single-ended 5V signals. What kind of input stage do the drivers have (standard optocouplers?)?
Have you taken into the account that PoKeysCNCaddon board is galvanically isolated from PoKeys?
-
Here is the manual for MCA808.
I did not consider that the CNCAddon is galvanically isolated- and this might be the problem.
The +5V line on Pokeys57E is connected to DIR+ and STEP+ (and ERC+, this is enable) signals on the servo drive.
Please advise on how to proceed.
-
At the moment, this is how I have the servo connected.
Works by jog, but only in one direction.
-
I resent the currently connected wiring - this is the correct one.
Pokeys.cncAdddon.Wiring1.MCA808.jpg
-
Hi Hanermo
After studying to your provided information, You can simply connect your drive in this way
PoKeysCNCaddon (10Pin) MCA808 X1 (DB9 male)
3 DIR ---------------------------> 1 DIR+
2 GND --------------------------> 6 DIR-
5 STEP ---------------------------> 2 PUL+
4 GND --------------------------> 7 PUL-
PoKeysCNCaddon is a Sourcing device (European style), it refers to GND.
Meanwhile you are trying to connect it as Sinking device (Asian style) which refers to VCC.
Regards,
Weerasak
-
Many thanks !
I reconnected as suggested, and it works first try.
I am * extremely * impressed, and will be repeating my very favourable impression of your technical support and products.
I hope to move to Mach4 soon, but wanted to get a working version first.
Servos now work as expected, on the test bench.
Machine is a scratch built VMC, in steel,about 2000 kg.
Using 32 mm ballscrews, and a submicron step size.
Again, I am very, very grateful.
-
I'm glad to hear it is working.
If you want to use powerful drives and motors with real big machine, Don't forget to implement safety limit to cut power source from drive system, otherwise they will ruin your machine.
Good luck.
Weerasak