[trademark]

machine is mid 90's dm4800 with mits m3 control.

We are having issues communicating with our pc.
This started yesterday after we had a big electrical storm.
before the storm we were able to send programs from the pc to the machine without issues.
after the storm we cannot send programs from the pc to the machine.
but we can send programs from the machine to the pc.

here are some things i have tried:
1: I have fiddled with the in/out parameters and tried different setups from this forum as well as others.
2: I have connected the pc to the other I/O port on the machine(the machine has 2 . the one on the control is parameter "0", The one on the monitor platform is parameter"1")
I swithed out the pc's to se if it was on the computer.
tried different cables.
I call mits tech support. After some discussion they suggested switching rs232 cables. But they also said i may have a board issue.


Reading in my manual it seems the cpu board handles the in/out communications.
It also says this board has a second in/out port to be used for maint.
one of the mits guys said to access this port by changing parameters.

questions:
How can i access this 2nd maint. port on the cpu board?
can i swap the cpu board with a spare that i have?
if i do this do i have to reinitilize the control?

Sorry to be so long winded. Trying to give as much info as possible.

Mike

[Caprirs]

There are two RS-232 ports on your machine. One is on the side of the front control panel and the other is on the side of the main power cabinet on the back of the machine. Open the main power cabinet and trace the cable from the external connector to the board in the control. You can bypass the external connector and cable and plug your RS-232 cable directly into either of the ports on the board in the control.

The RS-232 ports can be damaged. Mits used to repair them all the time, especially when customers had used the old data/printer switch boxes to connect multiple machines to a single PC. This created ground loops which would cause damage to the Mits boards and the users PC over time.

[trademark]

Thanks Caprirs:

We actually did have it hooked up thru one of the switch boxes.
Is it possible that the send port is ok and the recieve port is damaged???

i am assuming this damage is to the cpu board. (mc-161)
is this correct??

we have a spare board. If i change this board do i need to swap
the removable ic chips on the board??

[Caprirs]

Whenever I've had to swap MC-161 boards, I have not had to do any chip transfers. Your spare may be different though so check with the folks at Mitsubishi.

On the PC end, the RS-232 port will have two UARTs for transmit and receive. I don't know how Mitsubishi has their RS-232 arranged.

Since you've already tried a different PC, that points towards something in the machine. If you have a spare MC-161 card and are comfortable swapping it along with the obligatory re-initialize process, that may be worth trying.

Have you tried plugging the PC directly into the machine? No switch box?

[trademark]

we did the board swap last night. And we still have the same problem with the new board.
I do not know if this board was a good one .We purchased it off ebay.
we did take the switch box out .

we can send from cnc to pc with no problems.
but we cannot send from pc to cnc.

I am thinking i will send our spare to mits. and have them repair/check it
That way we know we have a good board.

Can you think of any other issue that may be causing this?
could it be a parameter problem? (see below)


btw. you need to swap one of the chips on the board before install.
I have attached mits. instruction sheet.
there is no initilizing after swap.
seems all the parameters are on this one chip???

[gm3211]

The big question, can you get an error at the CNC when sending into the controller from the PC. Does the machine give an alarm?

If, yes, the port is working most likely and maybe the parameters are miss-configured.