View Full Version : HELP!!! Cimco -- Use Parallel or Serial??

10-22-2008, 10:43 PM
Hi all,

First of all, let me start off by saying I know SQUAT about CNC machines or the software. But right now, I am the most technically-inclined person in my office when it comes to software so I've been put on the issue.

We recently purchased an OLD Leblond Makino milling center. The connection cable to the computer is a male to male connection. The computer that will run the MasterCam x3 software has both serial and parallel ports. Obviously, since the cable is a DB25, I'm trying to use the parallel port. However, when I try to configure the Cimco software, it doesn't even recognize the LPT1 port (though the computer itself does). I read earlier tonight that Cimco doesn't support parallel ports.

So I'm at a quandry. Can I use a different program other than Cimco? Is my solution as simple as using a parallel to serial converter?? Should I get a different cable --- DB25 to DB9 to allow me to use the serial port? Help! Help! Help!!!

10-23-2008, 12:25 AM
The port on the makino is more than likely a serial port, as I have never hear of a cnc machine having a parallel port. On many older devices they used a 25 pin serial port and the newer devices, like your computer, use a 9 pin serial port. I wouldn't just stick connecters on willy nilly, you might burn something out. Hopefully somebody will know if it is a standard serial port. Some devices have non standard wiring to the 25 pin connector.

10-23-2008, 12:40 AM
If it is a RS232 25 pin 'D' connector, you could make up a cable from this PDF I posted earlier http://www.cnczone.com/forums/showthread.php?t=66799
One way to tell if it is RS232 rather than parallel, is to measure the voltage on the pins WRT pin 7, check 2,3,4,5,6,8,20 and if any show + or - 9v or above, then it is RS232 not parallel.

10-23-2008, 01:05 AM
It's going to be a serial interface.
The fun part will be figuring out the baud rate, data bits, parity, stop bits, and which pins to jumper on the old Makino. A RS-232 breakout box is handy when interfacing to old machines.

I must be getting old as I remember when all RS-232 connections were 25 pin. The 9 pin interface along with the 25 pin parallel port (which used to be called a centronics interface) were inventions of IBM for the PC.

Hopefully someone will post specifics for your machine, otherwise it's going to be a lot of trial and error.

10-23-2008, 08:14 AM
Actually when I referred to the parallel port, I was talking about the one on the computer that will be running the software. The port on the machine in question is indeed an RS232. But since the cable is a 25-pin cable, that's why I was going to use the parallel port on the computer---but it doesn't see it. But I guess my question is should I have another cable made w/ a 9-pin plug so I can use the serial port that the software is currently seeing.

And you're definitely right about Bob about the "fun" part being the settings. The guy who will run the machine did it years ago but he doesn't really have any idea how to go about all this.

We've tried to find someone locally to come in and help us with this but no luck so far.