[Larken]

A lot of people have asked for a Step/dir to Analog board so people can run MACH3 and still use their Analog Amplifiers. Well i've finally made one.
Its Viper tune compatible and should have the features to do the job. It has a differential +- 10 volt differential analog output, current feedback input and enable output.
The loop time is much faster now and programmable up to 4000 samples /sec.

I am testing it on a AMC 80volt analog amp but I would like to have a few people test them on some larger amps on big mills.

[jeffserv]

I bought a board from CNC4PC that does this, used for spindle control, with PWM.... What do you expect to sell yours for?

Thanks,

[ech2o2]

Hi,
The mill is a lagun 3v model and comes with linear encoder that were used by the heidenhain tnc155. This controller is damaged and I just can't see spending money to fix it. I'm able to move the 3 axis manually as well as modify the speed of the machine and can conclude that the drives and motors are working well. I would like to simply replace the controller with a computer and Mach3 and your board would come in handy.
Drives: EL.GE AZE-CC4Q with 0+/-10V input
Motors: isoflux 4.4Nm Torque...3 of them

Do you think i can use the linear scales on the machine to connect to your step2linear board?
As Mach 3 does not run closed loop, does this mean that your new board will be able to compensate or detect for positional errors?
Tuning is done thru a 9pin or 25pin serial? can a usb to serial cable be used?
Thx for the help...and let me know as soon as the step2linear are ready...i want to try!

[Larken]

Hi,
The mill is a lagun 3v model and comes with linear encoder that were used by the heidenhain tnc155. This controller is damaged and I just can't see spending money to fix it. I'm able to move the 3 axis manually as well as modify the speed of the machine and can conclude that the drives and motors are working well. I would like to simply replace the controller with a computer and Mach3 and your board would come in handy.
Drives: EL.GE AZE-CC4Q with 0+/-10V input
Motors: isoflux 4.4Nm Torque...3 of them

Do you think i can use the linear scales on the machine to connect to your step2linear board?
As Mach 3 does not run closed loop, does this mean that your new board will be able to compensate or detect for positional errors?
Tuning is done thru a 9pin or 25pin serial? can a usb to serial cable be used?
Thx for the help...and let me know as soon as the step2linear are ready...i want to try!

- If you can get quadrature outputs from the linear scale then the board can read them. As long as there is no or very little backlash, the scale should work.
-Mach3 just outputs the Step/Dir count, which is the exact position it expects the machine to be at, in real time. The Step2lin and the drive take care to make sure the motor is at that position.
-Tuning can be done thru a USB port if you have a USB - serial converter. I don't put a USB on my drives because they are too sensitive to noise (which servo systems love to generate)
-I should have it ready in a week or two. I'm working on the current sense inputs. I'm using a differential opamp and it looks like it will be able to connect to most amps with no modifications. Some amps output differential and some single ended current monitoring. For the single ended, you just ground the minus input.


Larry K

[G59]

Your only about a day late for my situation. I ended up building a simple PWM to 0-10V analogue board for my AMC 100A40 spindle drive.
Being that I use Viper drives already on XYZ axis, your new product would of fit in nicely with the AMC spindle drive.
How much are you selling them for, as my analogue board is a temporary fix until I find something better.
With the mill having been down for a couple weeks already, work has backed up considerably, and if my little board fails, I for sure will be calling you. Just don't go crazy on pricing. LOL
35 to 60 bucks is what I'm looking at if I go with what's out there by the likes of Homan Designs and CNC4PC.

[Al_The_Man]

A lot of people have asked for a Step/dir to Analog board so people can run MACH3 and still use their Analog Amplifiers.
I am testing it on a AMC 80volt analog amp

But how will I be able to use my A-M-C drives that do not close the PID loop? I cannot close it to Mach.
Or does this board close an encoder loop?
Al.

[Larken]

I bought a board from CNC4PC that does this, used for spindle control, with PWM....
Thanks,

This isn't for the spindle drive, its for the axis servo drive.

But how will I be able to use my A-M-C drives that do not close the PID loop? I cannot close it to Mach.
Or does this board close an encoder loop?
Al.

Yes, it closes the loop and turns the analog drive into a closed loop step/dir drive, so the motor is locked waiting for step pulses to move it. You connect the encoder to the Step2linear board and tune the PID using a serial cable and vipertune.
(There was a board years ago called the pixie that did the same )

Al, do most drives supply a current monitor output, so i can sense load ? Is there a standard ?

[G59]

This isn't for the spindle drive, its for the axis servo drive.

That depends. Some Mach break out boards, like the one I use, don't have a spindle control port, . So to get around that, I use the A axis step and dir pins and convert them from PWM to a analogue voltage.
It works well and as soon as you have a manual for your board, I will look into it.

[Al_The_Man]

Al, do most drives supply a current monitor output, so i can sense load ? Is there a standard ?

I don't think there is a standard, for e.g. on AMC 1v out can represent a current (amp) value depending on switch setting the value also varies for each model model.
Al.

[Larken]

I don't think there is a standard, for e.g. on AMC 1v out can represent a current (amp) value depending on switch setting the value also varies for each model.
Al.

I'm getting some feedback from customers drives and these MTS automation drives have a + - 10 volt output on the current monitor.

Input/Output Interface: Analog Signals
Velocity Command Input -- Differential input 0 to ±10 Vdc (15 Vdc Max)
Auxiliary Input --- Differential input 0 to ±10 Vdc (15 Vdc Max)
Velocity Output --- Select 1.25, 2.07, 3.71, or 4.54 volts per 1000 rpm
Current Output ---- ±10 volts = ± Peak Current

The AMC drive i have is a is a 25A8 , it has 2 current output lines.

CURRENT MONITOR
Current Monitor. Analog output signal proportional to the actual current output. Scaling is 4.4 A/V. Measure relative to signal ground.

CURR REF OUT
Measures the command signal to the internal current-loop. This pin has a maximum output of ±7.25 V when the drive outputs maximum peak current.
Measure relative to signal ground

Al, are you familiar with the CURR REF OUT and what it does ?
Larry

[spectrumsas]

I'm getting some feedback from customers drives and these MTS automation drives have a + - 10 volt output on the current monitor.

Input/Output Interface: Analog Signals
Velocity Command Input -- Differential input 0 to ±10 Vdc (15 Vdc Max)
Auxiliary Input --- Differential input 0 to ±10 Vdc (15 Vdc Max)
Velocity Output --- Select 1.25, 2.07, 3.71, or 4.54 volts per 1000 rpm
Current Output ---- ±10 volts = ± Peak Current

The AMC drive i have is a is a 25A8 , it has 2 current output lines.

CURRENT MONITOR
Current Monitor. Analog output signal proportional to the actual current output. Scaling is 4.4 A/V. Measure relative to signal ground.

CURR REF OUT
Measures the command signal to the internal current-loop. This pin has a maximum output of ±7.25 V when the drive outputs maximum peak current.
Measure relative to signal ground

Al, are you familiar with the CURR REF OUT and what it does ?
Larry

Dear Sir
Please send me full details with connection diagrams to connect my hurco electrocraft max 400 analogue drives to run with mach3.
Sending photo of drive.

[jeffserv]

Sir,

Are you saying your interface will not work, if "Open Loop"; no encoder?


Thanks,

[Al_The_Man]

Sir,

Are you saying your interface will not work, if "Open Loop"; no encoder?


Thanks,

How do you run a servo open loop for CNC application??
Al.

[jeffserv]

Can this be used as a VFD control... no encoder feedback, Spindle Speed control? That is what I am asking... Maybe it cannot...

[Larken]

Can this be used as a VFD control... no encoder feedback, Spindle Speed control? That is what I am asking... Maybe it cannot...

No Jeff, its not for VFDs it for servo amplifiers that control a servo motor for the x,y,z, axis.

A VFD has a 0-10 volt input, but its too slow an input to control the motor in servo mode. The vfd has its own accel and decel settings.
An Analog servo amp has + and - 10 volt differential input and has very fast responce to send fwd and reverse power to the motor to hold high speed position.

A servo drive can be used to control a spindle in closed loop with an encoder, but its tricky because the spindle has a lot of mass and you can't suddenly change its speed or you may blow the drive. So s/w like Mach that could shut off while the spindle is running fast, could accidently stop sending step pulses to the drive, then the spinning mass of the motor generates a huge back emf. So its not recommended without a fail safe spindle controller.

So this thread isn't about spindles at this time, its just for servo controls

I for sure will be calling you. Just don't go crazy on pricing. LOL

Its listed on my viperservo.com site. (look for the ad here with the snake)

[Al_The_Man]

This is what I have on P1-9 pin.
I have never monitored it.
Al.

[ech2o2]

Hi Larry,
Would it work open loop or you think that the pwm "translation" to +/-10V will not be precise enough? You mentioned very little backlash to none...from your experience, what will be the magic number? If I need to change my encoders, would you recommend staying with linear encoders or switch to rotary? Do you have a good supplier to suggest for encoders? Thanks
Eric

[Larken]

Hi Larry,
Would it work open loop or you think that the pwm "translation" to +/-10V will not be precise enough? You mentioned very little backlash to none...from your experience, what will be the magic number? If I need to change my encoders, would you recommend staying with linear encoders or switch to rotary? Do you have a good supplier to suggest for encoders? Thanks
Eric

Eric, you have to run closed loop with an encoder, open loop would be totally useless. The USDIGITAL E5 or E6 series is the best one to get for the money. be sure to get differential outputs, and usually 1000 line is good.

The Step2Lin will be ready to ship at the end of the week . So i will send you a message about shipping.

One thing i added was a input to sense that there is power at the amplifier. It needed this to be safe, because if you turned the amp power off while the system was holding, then moved the motor, when you turned to power to the amp back on the motor would jump back violently since the encoder was still keeping the position.
So i have a opto-isolated input that will take up to 10 volts. You can just use a voltage divider off your main power that puts out 10 volts @ about 5 ma. Then when the step2lin sees the main power go off and come back on, it clears the encoder count and does a soft pwm startup.

On all my new boards, i've switched from the older 18F2331 to a 16bit DSPIC. My new PID loop is a bit improved from the older one, and i now have the Ki working much better. The sampling time is variable from 500-4000 samples per second with the Ki fixed at 1000. This makes the Ki not get unstable at high sampling rates and much more useful.

Larry

[chengcg2014]

But how will I be able to use my A-M-C drives that do not close the PID loop? I cannot close it to Mach.
Or does this board close an encoder loop?
Al.

yeah

[Larken]

Here is the actual board with the connections. The encoder connections are the same as my other viper drives (see v200 manual) .
I hope to have a full PDF for the Step2Lin soon. I will be adding to Vipertune to add data-logging, current display, 56k baud and other stuff.