[Mike4703]

Should the disable pin (11), be allowed to float or be pulled up to +V in? Grounding it will cause it to disable the output, but what does that mean as far as the relationship to the "active low" input signals and the common ground for the logic or signal ground (pin 12)?
The problem I'm having is that I have connected a new controller board, a Galil DMC-2142, and get good signal to the step and dir pins, but the motors don't move. I'm wondering if I have somehow triggered the disable? I have holding torque when powered up, and inputing movement from Mach3 causes square waves to show up on the step and direction pins but no movement occurs. What is going on?

[john-100]

Hi Mike ,

grounding the disable terminal 11 to the signal ground pin 12 disables the G201 drive , this reduces the motor current to zero
the drive will be enabled when the terminal 11 is open circuit

John

[Mike4703]

John,
This is a copy of my reply in to your question the in the General Electronics section. I wanted to keep a thread going here because it is monitored by Maris from Gecko.

The stepper pulses are total 5v amplitude and 6 mic sec duration. I noted that the base of the pulse is at -2.5 and the top at 2.5 though. Would that make a difference? Does the zero volt reference need to be pulled up or down? I attached a crummy photo of the oscilloscope screen but you can make it out. The drives logic ground was wired to the controllers ground. The duty cycle is 50%.

(see photo of occilloscope screen in General Electronics post)

[john-100]

Hi Mike

Having a second look at your picture of the scope trace
the scope input is AC coupled and the display looks correct for a 5V squarewave input

assuming you have connected the scope to the G201 terminals
I'd expect the drive to respond to the step pulses
when switching between 0V and +5V with repect to the signal ground terminal 12
are the Galil new controller board outputs TTL outputs ?

John

PS from the G201 manual -

quote
TERMINAL 10 Step
Connect the STEP line to this terminal.
These terminals can be driven with 3.3V or 5V logic. If 3.3V logic is used then the input current is -1mA for logic “0” and zero for
logic “1”. If 5V logic is used then the input current is -1mA for “0” logic and 0.67mA for logic “1”.

end quote

indicates to me the step ,direction and enable inputs are the inputs to 3.3V logic IC's
(as the input source a current of 1mA when connected to ground and sinks a current of 0.67mA when connected to +5V)

double check the output from the new controller is never goes negative with respect to ground or goes more positive than +5V

[Mariss Freimanis]

The step signal you describe sounds OK and the drive should turn the motor. The drive sounds OK as well because you said it has holding torque.

1) Is your STP/DIR signal source ground going to the G251 SIGNAL_GND terminal?

2) Are you perhaps sending the step pulses to the DIR input? Dumb things like that can happen. Ask me how I know.

Mariss

[Mike4703]

Thanks--I'll check out the wiring again for the step and dir signals. Not going to claim that could't happen. I've tried two different grounds from the Galil board and confirmed that it is correct by running it by Galil tech support, so that shouldn't be the problem. For pictures of the scope tracings and the full discussion see the thread under General Electronics/Help Needed-Controller steps not driving motor.

Mike

[Mike4703]

Maris,
I feeling a little stupid right now. The step and direction were reversed. Because I just grafted the new board into the existing setup and because this seems like such a simple thing I had made a wrong assumption about where the wires were going. Tested with continuity tester and sure enought the dir out was going to the stepper in. It now works fine.

Thanks,
Mike

[john-100]

Hi Mike ,

join the club

your not the first to get your wires crossed and your not going to be the last !!

its good to see no damage has been done

John