[Need TECH Help!]

So iam now going down the road of wiring my X,Y,Z servo drives(DMM- TECH) STEP & DIRECTION signals to my Dynomotion boards. The drives have I/O connector JP4 with Pin 10 (DIR-) Pin 11 (PUL+) Pin 22 (DIR+) Pin 23 (PUL-). (Also, i dont understand having the 2 different polarity STEP & DIR signals.)

The Input Circuit Reference in drive manual states that Voltage is + 5VDC +/- 10% and if higher voltage such as 12/24VDC is needed , to contact them. Is there a way to use the 24VDC option for STEP&DIRECTION and where would i wire these connections to on my Kflop, Kanalog, Konnect combo?

Troy

[Jim Dawson]

So iam now going down the road of wiring my X,Y,Z servo drives(DMM- TECH) STEP & DIRECTION signals to my Dynomotion boards.

The drives have I/O connector JP4 with Pin 10 (DIR-) Pin 11 (PUL+) Pin 22 (DIR+) Pin 23 (PUL-). (Also, i dont understand having the 2 different polarity STEP & DIR signals.)

I'm a bit confused here, your servo drives are Step & Direction input? Do they have an option for a +/- 10V analog input?

By bringing both pins out (+ & -) they allow you to wire the system either for NPN or PNP input. Gives you more flexibility in the controls. I normally like to use NPN where possible, more noise resistant. In that case 5V+ would be wired to the + pin, and the input would be wired to the - pin. This would require using the NPN output from the controller if it is available.

The Input Circuit Reference in drive manual states that Voltage is + 5VDC +/- 10% and if higher voltage such as 12/24VDC is needed , to contact them.

Is there a way to use the 24VDC option for STEP&DIRECTION and where would i wire these connections to on my Kflop, Kanalog, Konnect combo?

Troy

The Kflop board should output a 5V signal for the Step & Direction inputs of the Dynomotion boards. The encoders, if you have them will, connect to the Kanalog board, but this is where I am really confused. The Kanalog is designed to run a closed loop system with a +/- 10V analog signal out, with encoder feedback. External encoder feedback is not normally used with a Step & Direction drive. The encoder, if it exists, is normally used for position correction by the drive and is not wired to any other device. Having said that, there are systems that can use a second encoder input to ''double check'' the position and autocorrect. But those normally have one encoder on the leadscrew and one on the load or something like that. A rather uncommon system.

You won't be using 24V for the Step & Direction signals.

[Need TECH Help!]

Yes, Pin 25( AIN-) is Analog reference input NEGATIVE and Pin 13 (AIN+) is Analog reference input POSITIVE. Input Circuit Referance in manual saying they are Max ±12VDC and max 0.1 mA. My thinking on using the STEP&DIR is that this is more noise immune.
My last system was STEP&DIR with KFLOP,Kanalog and i used JP5 of KFLOP for my STEP & DIR signals. This connector allows for 4 axes. But i might get a wild hair and do a 5th axis at some point. So where would i wire the 5th axis if all axes are STEP&DIR?

KFLOP is able to do a dual closed loop system. I plan to later on adding glass scales or magnetic encoder scales on the axis slides to get closed loop at the table. Giving me a dual closed loop system. I have done a couple systems with glass scales closing the loop of stepper motors and got great results out of dovetail way machines. But this would be my first at a dual closed loop system using servo motor encoders and scales.

[m_c]

Troy,
the +/- signify that the step/dir inputs are differential. To make full use of differential signals, when one pin gets driven high, the other gets driven low. It makes things far less susceptible to noise, however you can normally drive them from a single ended source. As Jim says, you can connect the + to a power source and switch the - (NPN - set the KFlop to provide a open collector output), or connect the - to 0V and switch the positive (PNP - set the KFlop to provide LVTTL output).
NPN is the better option for a KFlop as they can only source 3.3V, however you need to be aware certain pins have pull down resistors, which may cause problems.
http://dynomotion.com/Help/StepAndDi...StepAndDir.htm lists the required information.

One thing that may be worth considering, is do the DMM drives support CW/CCW inputs? If they do, then it eliminates the headaches with step/dir timing.

If you want to make use of the differential inputs, you'd have to buy or make a differential driver board to take the single ended KFlop outputs, and convert them to differential. I made a board for my latest mill, that interfaces with the JP5 connector, and allows me via jumpers to move connections between the Kanalog encoder inputs, and the differential driver. CNC4PC supply line driver boards - https://cnc4pc.com/differential-line-driver.html
A photo of my board can be found at - https://www.flickr.com/photos/mc_mtb...7674158270440/ I could send you a bare PCB, along with the required surface mount caps/resistors if you like, however you would need to source the line driver chip, jumpers, and connectors (I used identical ones to Dynomotion boards), and be able to solder it together.

Jim, KFlop will allow you to run step/dir closed loop, and also dual closed loop I.e. run a servo closed loop, combined with a linear scale for more accuracy. With a step/dir servo system, the only advantage would be to see what the servos are actually doing, which should help with tuning. Under normal running, I don't really see much advantage, although it may help catch following errors should they occur.
Kanalog doesn't close the loop, it simply provides +/-10V outputs/inputs, differential encoder inputs, along with extra IO, which the KFlop fully controls. It's an extremely flexible system, in that you can configure each of the 8 channels to work however you want with the available inputs/outputs.

[Need TECH Help!]

So do u think that +/- 10vdc is just as noise immune as step, Dir?

[Jim Dawson]

Looks like I need to actually read my Kflop/Kanalog documentation again. It's been a few years since I have looked at it. I have only installed one on a customer machine, and that was a few years ago.

I have found that the analog motor command signal to be very reliable. I have had very good luck with magnetic scales on the table, had them on my machines for a few years now. And the real advantage is the backlash (within reason) and any lead screw error is automatically compensated. I have no encoders on the leadscrew or motors.

[m_c]

Analog should be far more tolerant than single ended step/dir, however it can be a bit more effort to set up and tune well.

Running step/dir and having encoder feedback to the kflop, would mean any noise problems should be detected, whereas if you're running blind, then axes can still drift.
It's worth noting that even if you run step/dir with encoder feedback to the kflop, the kflop won't compensate for lost steps. It'll simply result in the following error increasing. I've got a small digitising machine running closed loop with a KStep and linear scales, and if you stall/manually move a stepper, it is not compensated for. It simply increases the following error until it reaches the limit and disables.

The key to noise immunity, is good grounding practise, and differential wiring.

[Need TECH Help!]

...I've got a small digitising machine running closed loop with a KStep and linear scales, and if you stall/manually move a stepper, it is not compensated for. It simply increases the following error until it reaches the limit and disables.
.....

Not sure i follow what you are saying here as i had a knee mill with steppers and glass scales and loop was closed so that KFLOP would compensate. If i cut a 1.0" circle in open loop the circle would be around .002-.003 out of round. Running this with Closed Loop turned on the circle would be within .001" round and on size.

[Need TECH Help!]

The drive manual says to use twisted pair for the analog +/- 10v signal. Does this mean one pair for + pin and one pair for - pin? Using a total of 4 wires.

[TomKerekes]

Hi Troy,

Yes I think Analog Velocity Mode would be your best option. That is the simplest way to get dual loop operation when you go to Linear Scales. The Drive will form a velocity loop itself based on the rotary encoder and then KFLOP+Kanalog can close the Linear Scales Position Loop.

The drive manual says to use twisted pair for the analog +/- 10v signal. Does this mean one pair for + pin and one pair for - pin? Using a total of 4 wires.

No. Just use a single pair of wires. Connect the - pin to Kanalog GND and the + pin to a Kanalog DAC Output.

HTH
Regards

[Need TECH Help!]

Hay Tom,
When i get ready to do dual loop, does the encoders on motors need to be wired to KFLOP/Kanalog also? There is a encoder output connector on drive. It is A+,A-,B+,B- and Z+,Z-. Was planing to at lest wire up the Z index for referencing of machine.

Thanks,
Troy

[TomKerekes]

Hi Troy,

When i get ready to do dual loop, does the encoders on motors need to be wired to KFLOP/Kanalog also?

No. The encoder on the motor can remain connected to the drive. The Drive will then be controlling the inner velocity loop. The Motor's Position will not need to be provided to KFLOP or Kanalog. The Drive will need to be tuned for good tight velocity control.

There is a encoder output connector on drive. It is A+,A-,B+,B- and Z+,Z-. Was planing to at lest wire up the Z index for referencing of machine.

Yes. When not using linear scales you can wire ABZ to Kanalog to close the position loop based on the motor's encoder. Later when using Linear Scales the AB from the Scales can be connected to Kanalog instead. The Z from the Drive can remain if desired and the Linear Scales don't have something better. The Z can be connected to any unused A or B input.

HTH
Regards

[Need TECH Help!]

Still working on my wiring diagram for the servo drives. Now i am working on the Alarm output from servo drive.
DYN4 pg 15 attachment is example from drive manual. They show a 1K ohm resistance that i dont understand. Is this the resistance of this pin? I dont understand how this circuit is supposed to work.

How would i wire this ouput into Kanalog Opto input 0? Would minus side of 24VDC supply be wired to Pin 5 (COM) of drive, then Pin 18 of drive wired to Kanalog Opto 0 minus pin and plus side of 24VDC supply to Kanalog Opto 0 plus pin?

Thanks for any help,
Troy

[TomKerekes]

Hi Troy,

Correct. As in the opto coupler diagram, Kanalog has the resistor built in.so no need to add it.

Regards

[Need TECH Help!]

Hi Tom,
If I was too wire to a Konnect input 0, would +24vdc go to J1 pin0 of Konnect, -24vdc to Pin5 (COM) of drive then Pin 18(Alarm) of drive to Konnect input 0?
Troy

[TomKerekes]

Correct

[TomKerekes]

I assume you meant the GND of the +24V supply, not -24V

[Need TECH Help!]

Oops, yes, the GND/- side.
Thanks

[Need TECH Help!]

My drives have an output pin for Monitoring the current being used in CW or CCW direction. Pin 21 of drive does this. It outputs 0-3.3V. 0volts being equal to -30amps, 1.65V equal to 0amps and 3.3V equal to +30amps. To wire this to Kanalog i would wire Pin 21 of drive to Kanalog JP6 terminal input 0 and wire GND Pin 9 of drive to a GND pin of Kanalog JP6 terminal?

Also, if the above connection is correct can it be used to display a percentage load meter in KMotionCNC for an axis?

Thanks,
Troy

[TomKerekes]

Hi Troy,

That should be possible. The KMotionCNC Screen Editor allows you to add DRO type readouts and simple Vertical Bar Graphs. See the Screen ShowInstantFeedRate3AxisBar.scr. And the C Program ShowInstantVelocityDROBar.c to compute a value and put it in the DRO and Set the Vertical Bar Graph. Of course the example computse and displays the current feedrate. You would change that to instead read in the ADC value and scale and display it instead as a Current.

HTH
Regards