View Full Version : RS232 for Mitsubishi RA90

04-19-2007, 01:21 PM
A customer of ours, just purchased a Mitsubishi Wired EDM Machine RA90. They are currently loading from floppy disks of the NC programs. They want to connect an RS232 cable and use Predator DNC. They have serveral machines already on Predator and just want to send and receive.

Does anyone know the wiring of the cable and parameters for this machine?
I tried to get ahold of Mitsubishi now for serveral days and no response....

Any help is greatly appreciated!

Greg Mercurio
Shop Floor Automations
(877)611-5825 Toll Free ext 1001

Email to: gregm@shopfloorautomations.com

04-19-2007, 01:52 PM
Greg, Is the RA90 a machine model? If the Mitsubishi controller model itself is known, then the manuals should be on the MEAU website, did you look there yet?

04-19-2007, 10:47 PM
From what the customer tells me, that is the control (I really do not believe it). Doing a quick seaarch on Google there are several of these machines RA90 but nothing with details....

Still waiting on reply from Mitsubishi....

Robin Hewitt
04-25-2007, 09:15 AM
I used to do RS232 for a living, it should not be complicated :)

The United Nations set up the CCITT (Committee Consultative International Telephone and Telegraphic in French) who chose the American RS232 as the standard for us all. The definition included the pin out for 2 channels on a 25 pin D type plug, but usually only the first was used so there are a lot of spare pins.

Then IBM didn't have room for two sockets on the back of their standard PC card adaptor so they reinvented it as a 9 pin connection making it the opposite gender to their games port to avoid confusion.

These should be the only two pin outs you will find.

9-25 way adaptors are freely available, the "modem" cable usually has loopbacks on the handshaking lines and crosses transmit and receive.

Robin Hewitt
04-25-2007, 09:27 AM
PS: If it's 9 way both ends and doesn't have the crossover built in for straight through...

2-3 rx-tx
3-2 tx-rx
4-6 dtr-dsr
5-5 gnd
6-4 dsr-dtr
7-8 rts-cts
8-7 cts-rts
Pin 9 is ring indicator and never used.

If in doubt you could switch on and measure the volts on pins 2 and 3, tx will be driven -12v, rx will be floating.