Parallel to Serial

[cbcnc]

Is it possible to convert LPT parallel output to serial output in order to use a controller that uses a Com port input?

Chris

[Al_The_Man]

You could do it with a USART ic, I used to use Intersil IM6402/6403 but I don't know wether you can still get them but there should be a USART out there that would do, these IC's transmit and recieve parallel to serial, otherwise a PIC processor would probabally do also.
Al.

[Chris D]

Originally Posted by cbcnc Is it possible to convert LPT parallel output to serial output in order to use a controller that uses a Com port input? Chris

Search for parallel to serieal on the Jameco website. I believe they have a device that can do that - around $50.00 in a dongle sized device.

Chris

[cbcnc]

Is it as simple as that? In other words to just turn the parallel bytes into a bitstream and a standard controller could read them?
To be more specific I have an older API Controls DM-2205i stepper controller. There are no inputs for step and direction. All communications are done thru the Com port. Can I drive that with say TurboCNC or Mach 2/3 if the parallel bytes are turned ino serial data?
I'm digging back into what little knowledge I have about COM port devices. Doesn't each device in a daisy chain have an address and will listen if data is sent to that address?
On the parallel port the data for each controller or axis (2 bits) is mixed into 1 or 2 bytes. It seems that more translation would be necessary for each controller.
I know I am thinking out loud and am beginning to answer my own question.
I had better do some more reading before I ask any more stupid questions. I do appreciate your answers.

Thanks,
Chris

[CLaNZeR]

The parallel port sends data out in parallel. Each pins represents a bit.
So if you wanted to send out 1 byte of data you would break the byte down into bits and use 8 pins by setting them high or low to represent the byte.

The serial port in basic use, uses 2 wires, one for transmit and one for recieve.
You transmit bytes back and forth by breaking them down into bits and pulsing the transmit line high or low to correspond to the bits.

You will probably find that your controller with serial port has a processor inside it that expects to receive serial data from this port.
Serial data is sent from the software running on your computer to the processor and the commands are then interepted into step and direction for each Axis.
The processor pins now control the correct Step and direction pulses on the motor control circuit.

With a parallel port each pin can be controlled indidually by the software running on the computer and usually the pins are then taken straight out to the Motor control circuit.

So your main problem really is knowing what custom codes are sent down to the serial controller for step and direction and also finding software that suits this controller and matches the same protocol it expects.

With parallel port it is easy to configure most software out there as you just tell it what pins do the X,Y,Z steps and direction.

Hope this helps

Regards

Sean.

[ViperTX]

cbcnc...without step and direction you should look at EMC. I don't believe TurboCNC or MachX will work without step/direction.