[rubberducky125]

I just got all the electronics to convert my g0704 to CNC. I've got everything wired up but I'm not getting any movement from the stepper motor however it is locking into place when I turn the power supply to the motor on so I know it's getting power. I think I may have an issue with my breakout board. If I measure at the parallel port directly I'm getting 5V, when I measure from the pins on the breakout board I'm getting 2V. Is that normal? If I measure while I'm jogging in mach 3 I can see the voltage change but the motor doesn't move. Does anybody know what could be going on?

[john-100]

Hi

assuming your measuring the output terminal blocks 2 to 9 ( not the pins on the 25 connector)
the responce to your jogging indicates the C10 must be enabled and the boards terminals 2 - 9 set as outputs OK

check the C10 boards 5V supply is 5V
then check the step and direction outputs when they are disconnected from the stepper driver inputs
if they now switch between 0V and +5V the stepper driver must be overloadind the C10 outputs
( its easier to see the direction outputs switch between 0V & 5V , the step outputs will switch too quickly and you will see an average voltage )

what stepper drivers are you using and how have you connected them to the C10 BOB ?

john

[rubberducky125]

I was checking them while they were still connected, I'll try it with them disconnected when I get home today. I'm using 2 KL-5056 drivers and 1 KL-8070 and have them wired according to this diagram

http://www.automationtechnologiesinc...56DWithC10.pdf

I've only got one stepper hooked up to one of the kl-5056 drivers, the other 2 drivers have no motor hooked to them. I don't think this could be the issue, but I'm not all that familiar with these type of electronics so could that possibly cause the issue I'm seeing?

Thank you for the response

[rubberducky125]

Also the power light on the breakout board would turn one with just the parallel port connected and the power supply turned off. Form everything I've seen, that isn't normal.

[john-100]

Hi

the power indicator being on with just the printer cable connected is possible

the C10 board can work to a degree without the 5V power supply working, provided some of the printer ports are at a logic 1 ( +4 to 5V )


the four 74ACT245N CMOS octal buffer IC's require very little power when the inputs are static or are slowly changing


without a working 5V supply , some of the 5V logic signal on an input pin wiil flow , via the 74ACT245 input protection circuit , to the IC's +5V supply line connection to pin 20

this will not only provide a lower than nornal power to its own circuits but to the C10's other 4 IC's and the red LED power indicator

( the board will stop working if all 12 printer port output pins go to logic 0 (0V )

did you check the 5V power supply output is 5V ?

the stepper driver inputs are only connect to the LED inside an optoisolator and a resistor of about 300 ohms
with C10's step and drive outputs of a 5V , I'd expect the LED current being a maximum of 10mA ( 1/5 of the IC's output pin limit of + or - 50mA)

John



Fairchild Semiconductor Corporation
74ACT245 bi directional octal buffer :-

Attachment 287668


Texas instuments
Designing With Logic

input protection - see figure 7 on page 9

[rubberducky125]

It was an issue with the power supply, one of the wires wasn't getting a good connection, thanks for your help John, really apppericate it.

[john-100]

great news - you have fixed it

Its the red power LED being on when the power is off that confuses the issue

john