Enable = False while doing other stuff?

[murphy625]

I have been wrestling with the "Operational Code" and the order in which things happen with my system.

To make things short, I want to make the servo enable circuit false while the machine is doing other operations. The servo drive would stay powered on, but it would not be under torque.

Is there any downside to doing this? What happens if the servo enable = false and the machine gets moved and then the servo enable goes positive? Will this cause a problem with jerking? I'm thinking the camsoft interface is going to want to try keeping position even though it can't..

This machine has jerked on me before and I never knew why it was doing it. I am quickly learning that making this thing do what I want is easy...Preventing it from doing unexpected things when unusual circumstances occur is turning out to be an educational experience.

Thanks for your help.. This forum rocks... No wonder it has 10,000 members!

Murphy

[Al_The_Man]

I mentioned this in an earlier post, look up the SH 'Servo Here' code for the Galil, it allows phyisical movement of the axis when not being powered, when power up is restored the axis assumes this position and does not loose counts etc.
Should be done at e-stop etc, you have to provide a loop that constantly outputs SH.
Al

[murphy625]

Thanks AL,

I know you posted that in another post.. I could not figure out where it was but I knew you were the one who told me that...

Thanks!!!

[murphy625]

AhAH!!! I just figured out how to use Servo Here (SH) and Motor Off (MO).. (Thanks to AL THE MAN!)

But I am a little confused.

The Galil manual says that my amp enable should be TTL active high.. (This means +5V when the motor should be on right??)
My AmpEnable is connected to an OPTO22 board with an ODC5R (Output DC 5V Reed Relay). Anyhow, the AmpEnable signal is 5volts when my motor should be on and my OPTO board wants the pin shorted to ground to turn on. (which means to me that I need active low)

I should note that I have had my Ampenable signal connected to a normal output and was turning it on and off manually during testing.. This is the first time I have actually done testing with it connected to the AmpEnableX pin on the ICM2900.

Anyhow, to make a long story short, it would seem that I need to replace a 7407 IC chip inside my ICM2900 with a 7406 chip..( Page 14 chpt 2 of the galil manual).
Are all 7406 IC chips created equal ?? Can I get this from Radio Shack or Ebay?? Or is this something I need to call Galil about??

Thanks!!!
Murphy

[Al_The_Man]

The 7407 ic will invert the Enable signals, If you have local Electronics supply places like Radio shack, Virually any flavour of 7407 will work. They are only a few cents, if you have to bring one in the shipping will be 10x the IC.
If you only have one to invert, you could use a single transistor to act as an inverter, I keep a stock of 2n7000 on hand for this purpose.
Al

[keithorr]

Search "7406" on ebay and you'll find a store that sells 10 chips for a dollar plus 5.95 shipping. Three days in the mail. Radio Shack doesn't have em.

I am also figuring out a retro. The terminology is difficult for me to understand. Enable high, true high, floating high, sink, source,... it sure isn't like the knob and tube wiring in the milking barn.

The opto22 parts should integrate without any trouble. Which board you are using when your write "board wants pin shorted to ground"? I use grayhill boards that allow either negative true or positive true logic. They only hold four modules, but I don't need a header cable to connect. I can wire them a few different ways depending on the application.

There is a schematic for a opto22 board here. Is this what you are using?

http://www.opto22.com/asset/document...data_sheet.pdf

If so, maybe someone else can take a look and decipher.

[Al_The_Man]

The ODC5R is negative logic only, AFAIK.
Some of the Opto boards that have termination screws for both logic and power can be configured for both, but you have to use a relay that is capable of both sink & source logic.
Al

[murphy625]

Originally Posted by keithorr Search "7406" on ebay and you'll find a store that sells 10 chips for a dollar plus 5.95 shipping. Three days in the mail. Radio Shack doesn't have em. I am also figuring out a retro. The terminology is difficult for me to understand. Enable high, true high, floating high, sink, source,... it sure isn't like the knob and tube wiring in the milking barn. The opto22 parts should integrate without any trouble. Which board you are using when your write "board wants pin shorted to ground"? I use grayhill boards that allow either negative true or positive true logic. They only hold four modules, but I don't need a header cable to connect. I can wire them a few different ways depending on the application. There is a schematic for a opto22 board here. Is this what you are using? http://www.opto22.com/asset/document...data_sheet.pdf If so, maybe someone else can take a look and decipher.

Yes.. that pdf file is what I am using.. ODC5R.. I have that pluged into an opto22 PB16T board that I hook up all outputs from my ICM2900 to.
Here is the link to the board.
http://www.opto22.com/asset/document...data_sheet.pdf
(Opto or no opto option, I like the extra layer of isolation the optos give me.. (even though the ODC5R is a dry contact its all I had to work with)
I dont get the terminology either.. But I do understand the phrase "Sink it to Ground"

I called around to my local electronics places. No one has this darn chip...

Murphy