VSD-A Servo drive documentation

[Xerxes]

Purpose of this thread is to discuss about drive documentation and announce documentation changes. The more discussion, the better.

[Xerxes]

I just added some information about designing a power supply for drives in VSD-A documentation. Check it out at:
http://www.granitedevices.fi/index.php?id=8

It is best not to follow that guide too tightly because it simplifies things very much. Previous experience in PSU building may help preventing magic smoke from escaping the circuits :-)

[freezy]

Hi,

I added GDTool manual into Granite Devices webpage:
http://www.granitedevices.fi/pub_fil.../GDtool031.pdf
Next version of GDTool is under work so GDTool document will be updated after new software version is released.

[Xerxes]

VSD-A data sheet got just updated (version 0.40). I added chapters about known limitations and supported motor types.

[daedalus]

having read the datasheet for the drive and your tuning software, i noticed that you mention torque control as an option in the drive datasheet, but there doesnt seem to be a choice for it in the tuning software.

Also how does torque control via step / dir work? do you keep an internal desired torque, then step it up / down by a fixed amount? is that fixed amount user specified? For torque it would be much more useful to have pwm / dir control, as i dont know any motion control hardware that outputs step/dir, its usually just pwm or analog.

Also do you know if anyones working on spi interfacing your drives to EMC / mach?

[Xerxes]

You're right about torque control. It is supported but not shown in GDtool because it's only a temporary tuning software. Timo (freezy in CNCzone) is working on the next version of GDtool which should unleash all the features of the drive. However, I can write instructions about how to set torque mode on manually if needed. User desired step/dir command scaling can be done in all modes.

Currently step/dir or SPI is used for all modes. Hardware has built-in capability for PWM mode but it's not yet implemented in firmware (I'm working on it).

I haven't heard anything about direct SPI support. I have taken a look in EMC internals and I might try to write some a driver for it some day. But it would be faster if some EMC expert would be available for assistance

[daedalus]

Thanks for the info. One thing that might be helpful is if you had a list of planned updates / features (subject to change of course) for people to look at somewhere.

The step/dir scaling is pretty important, and probably should be on the datasheet, as people with P5's are going to need it if they have 10,000 step / rev (x4 decoding).

[buckie555]

Currently step/dir or SPI is used for all modes. Hardware has built-in capability for PWM mode but it's not yet implemented in firmware (I'm working on it).

I also plan on using EMC and the MESA 5i20 card so PWM mode for torque control would be a very welcome addition for me as well. Any ideas on when this is likely to be available?

Will existing customers be able to upgrade their firmware? What cabling/host application requirements are there?

[Xerxes]

Well, it seems that there is more need for PWM than I first thought so I'll try to implement it sooner. I'll try to experiment with it this week. If everything goes smoothly, it could be available in couple of weeks.

Firmware is upgradeable and requires nothing more than one jumper block Tuning software comes with flasher software which uploads firmware thru SPI tuning cable.

Planned features at the moment:
-Stepper support (open & closed loop)
-PWM input
-Controllled hard stop homing option (no home switch needed)
-32 bit absolute position commands via SPI in addition to 16 bit (good for point-to-point applications with long moves)

[Xerxes]

Documentation got updated again. It now includes full listing of features to reduce need of guessing

http://granitedevices.fi/index.php?id=15

[Eson]

Will there be stepper support for the drive? I read somewhere about a firmware upgrade. Is this true?

Maybe wrong thread...sorry

[Xerxes]

Eson,

Yes, stepper support will be in upcoming firmware version 110. VSD-A won't reach the optimal 2-phase stepper performance because it has 3-phase output but it seems to perform quite well anyway.