EMCO PC Mill 50 RS485 Data Capture

I’m excited to say that I now have a running Emco PC Mill 50! Currently it is running on the stock control (Emco ISA PC card + Axis Controller). I really like the stock controls functionality (it closely emulates a Fanuc O-M control, which I am very familiar with from my day job). That said, it has some limitations, most concerning to me is a very small memory for programs (~200 lines or so I have read). As part of my mad scramble to get the control running, I spent several (ok, way too many) days working with software dis-assemblers (IDA and GHIDRA) looking at the EMCO software package.

I found some pretty cool things! One thing I found is the factory service tech passwords for the configuration program (WinCfg V1.1, try each of the following words: SERVICE, CONTROL, SUPERVISOR). Using these passwords, I was able to turn on the built in RS485 data capture in the software- this saves a log of all communication to and from the control. I have attached this file below. I know that I still have work to do in terms of mapping commands to machine actions, but this should be fairly trivial with a working machine.

What I hope to do, and would really like this communities assistance with, is upgrading the control on this machine. I want to do it differently than I have seen done before. I want to retain the machine itself in the factory configuration, and upgrade the computer itself. Essentially, the system as it stands now is an 8088 Microprocessor with some memory on an ISA card in the PC, connected to the machine over half duplex RS485. The machine itself uses a 80C196 micro and an 8088 to control the axes and IO. My vision for the updated control system would be to use open source hardware (I think Mesa has an FPGA card that will do this) to drive the RS485 link to the machine, and Linuxcnc to control it. The major advantage to this as I see it, is the ability to drip feed programs, resulting in a nearly unlimited program length.
Examining the project, it seems there are 4 logical phases:
1.) Decode RS485 communications, build command table
2.) Select/Build new computer side hardware (computer + new interface card)
3.) Install and configure Linuxcnc (this is honestly what makes me the most nervous- I have programmed my share of PLC’s/Automation controllers, but have minimal experience with LinuxCNC)
4.) Integrate the system and troubleshoot.

I would be very interested in your feedback/expertise with this!

Thanks,

Travis

I'm struggling to understand why connect via RS485 when Linuxcnc will allow nearly unlimited program length without drip feeding anything. Just plug a 5i25 into your ISA slot and place the Mesa board best suited to control your machine at the other end of the cable.

ISA slot or do you mean PCI / PCIe

Clive wrote:

ISA slot or do you mean PCI / PCIe

Have you any idea how long it is since i've owned a PC with an expansion slot of any kind?

So 1990's

rodw wrote:

Clive wrote:

ISA slot or do you mean PCI / PCIe

Have you any idea how long it is since i've owned a PC with an expansion slot of any kind?

So 1990's

What not even a SCSI

Clive wrote:

What not even a SCSI

They were some archaic device from Adaptec weren't they? I think they lasted a bit longer 'cos I was in the printing industry so we had scanners and the like still connected via SCSII in the late 90's