Hi Ive acquired 2 areotech servo amplifiers and servos i need to know how to get started wiring them just to experiment at first then for my lathe areotech BA20-160
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Hi Ive acquired 2 areotech servo amplifiers and servos i need to know how to get started wiring them just to experiment at first then for my lathe areotech BA20-160
The manuals should be on the web site, I have them in PDF if you have a problem.
Al.
Hi Al Thank You very much for the reply..I have the manual....but i don't understand servo motor control. i understand stepper motor. maybe you can point me in some basic direction
Industrial servo's are commonly driven with what is commonly called a +/-10 vdc analog control voltage. If yours use this method, they work as follows:
The polarity (+ or -) tells the direction to go which is not unlike your "direction" bit on a step/direction stepper.
The magnitude of the voltage (0 versus 1 versus or 10) tells how fast. Where relatively speaking, a 0.00 volt signal is no speed in either direction and +5 volts is perhaps 50% of the rated speed of the motor assuming that rated voltage is applied at +10vdc or 100%. If the signal is -5 volts, the motor runs at half speed in the opposite direction.
In steppers, you'd throw more pulses faster to make the motor run faster. In a servo, you increase the ON time of the PWM "H bridge" which is driving the motor to make it run faster.
Check out Unitrode/TI. They have some servo control IC's that have appications notes that explain a lot about how servo's work and they feed back speed and/or position signals to the servo controller. I think UC3637 is one that does a good job of explaining.
Hi NCCams thank for the info i have a CMC 2620 servo and a areotech amplifier do you have a link to help me experment with these two devices
OK i found this i guess i need a digital controller can anyone elaborate on this
The hook up is fairly straight forward, if you have the commutation AND encoder option then the three commutation outputs go to the Aerotech drive and the encoder will split off and go to your controller, whatever that maybe, they usually come with a 1000p/rev differential encoder.Quote:
Originally Posted by frankg521
If you want to just hook it and and try turning the motor, a ±9vdc drive signal can be made with a 9v battery and a potentiometer to the analogue input.
If you want to search for some info google Brushless DC servo.
And also search quadrature encoder.
Al.
The BA amp is ±10vdc analogue control, not digital, you can get highend controller cards or CNC systems that use this method (ANALOGUE) or if you use the common hobbiest method of step & direction through the parallel port, Mach etc, you will need a step/dir to analogue convertor. There is one used in the forums here, the name escapes me at the moment.Quote:
Originally Posted by frankg521
Al.
I have to make a correction, in your original post you mentioned you had Aerotech drives AND motors, but if you have the BA Brushless DC amp and a CMC2620 motor, IIANM this is a DC brushed motor, if so you will have to set the BA for 60° commutation and just use the U V outputs on the drive.Quote:
Originally Posted by frankg521
It works fine in this mode as a DC brushed amplifer/drive.
Al.
There is this neat tool called Google that doesn't require much input to tell you what you want/need to know.
In this cae, simply by typing in "CMC 2620 servo", the following came up right away:
http://www.cmccontrols.com/brush_ser...atform2600.asp
Go down about 2/3 the way of the page.
For "areotech" the same google search via "areotech servo amp" yielded:
http://www.aerotech.com/products/amps/4020order.html
You should be able to dowload what you need to figure out what you want/need to know.
Just be sure to choose the correct amp that matches what you have and, providing it matches your servo and control scheme input, you should be able to experiment enough to make the motors rotate in a predictable direction.
The Aerotech link is for a DC amp, I think Frank has a the Aerotech BA20 DCBL/DC amp & a DC motor, slightly different animal, but I have them working with CMC motors with no problem.Quote:
Originally Posted by NC Cams
You just do not use the commutation feedback.
In the 60° mode, U & V act as a typical H bridge DC drive.
Al.
Here is a usefull engineering reference for hook up etc.Quote:
Originally Posted by frankg521
http://www.a-m-c.com/download/docume...l/engnotes.pdf
Al
My intent of post #10 was more of SHOWING HOW a member can use a very few key word terms and Google search as opposed to merely ANSWERING his question..
Sort of analogous to "feed a man who's hungry and he'll remain hunger free for a day, tech him to fish, he'll won't have to ever have to fear being hungry again".
A nice primer on the basics of BRUSH type motor drives for ANALOG (+/-10) based drives is found in the Unitrode/TI UC3637 IC. Get ahold of the U-102 application note from the same firm.
By the way, Unitrode/TI also has a number of BRUSHLESS drive IC's as well as STEPPER drive IC"s for the fans of same - ditto that for the appropriate appliccations notes.
Good fish food as well.
With the Unitrode/TI info, the member should be able to do a lot more successful fishing.
Thanks for posting that link Al... good info.
Skyko makes that pixie card that I think you were referring to btw. The one that converts 5v digital to 10vdc analog. However, people are warning that they are not responding to inquiries at the moment.
I wonder if the digital-to-analog (0-10v optional) feature that the G-Rex controllers offer means that it is capable of driving a 10vdc analog amp like the BA series? I have wondered about this after reading the G-Rex description PDF and seeing this option.
is this true al can i use G-Rex to control my analog amplifier
Frank
I am not familiar with the G-Rex, but the manual should tell you.
Al.
From the G100_DESCRIPTION.pdf:
"5) 4 Digital to analog outputs. Each output is a 0 to 5V (0 to 10V optional) op-amp output and 8-bit resolution"
I'm not sure if this means it can do it but it would be cool if it could!
No. The G-Rex doesn't support closed-loop operation.
Mariss
----- Original Message -----
From: [email protected]
To: [email protected]
Sent: Wednesday, July 18, 2007 7:26 AM
Subject: G-Rex
Can i use G-Rex to drive _+ 10 volts analog servo amplivier and servo
Frank
Thanks for finding that out Frank. That's too bad. So, if the G-rex controller doesn't support a closed-loop operation then does that mean that it's up to the drives to control the feedback loop? Sorry for my ignorance!
yantra3d, I believe that is a question for Al ,,,as for my education on servos is just starting...But!!!! i believe on the Mach support forum geri21 sead that G-Rex will soon support closed loop but no time frame from Gecko.. but i could be wrong i think i read every post on that page ........Quote:
Originally Posted by yantra3d
Frank
Pretty much in a nut shell, parallel port systems, Mach for e.g. do not close the loop in the control like say a dedicated motion card or one of the major CNC systems, they issue the command out of the port and it is up to the individual controllers to issue or keep track of each servo.Quote:
Originally Posted by yantra3d
With true closed loop you can institute electronic gearing used in helical milling and threading, or servo slaveing.
and also monitor following error etc.
I have not investigated the Mach venture into integrating the Galil (closed loop) motion card yet.
Al.
But couldn't you consider a servo equipped with an incremental encoder - looped into a G320 to be a "closed-loop velocity servo system"? I doubt the gecko drive calculates advanced algorithms and all but it must somehow analyze the feedback from the encoder and make a real-time adjustment that effects the servos velocity otherwise what would be the point of the encoder? I'm lost on the whole closed-loop concept! :confused:
In a system where the loop is closed back to the controller means that the Controller, where the servo moves and trajectory are calculated, has feed back via the encoders for all axis to enable constant update based on the feedback obtained.
Al.