Transfer programs to a MORI SEIKI ZL25 with FANUC MSC-518 RS-232 through MOXA DE-211

Hi,

I'm struggling with the new setup and I hope you can point me to the right direction.
So we have the old setup from MOXA C320 (C32010T PCI board + C32030T CPU module + 2x C32045T UART modules) up and running, and we wanted to buy the same setup because some ports aren't working, but it's not available anymore. MOXA has recommended to use the DE-211 instead, so that we can have longer distances between PC and CNC machines because of LAN.
And unfortunately it's not working but I'm not sure what is not working and why. I have tested the MOXA DE-211 with a loopback adapter, and it seems to work.
We have two separate software for program transfer. One is for the older machines with RS-232 (and I guess without MAPPS?) (it's a custom programmed software). And the other is the MORI-SERVER software (I guess for newer machines with LAN and MAPPS?). Now it doesn't really seem to matter which one I try to replace with the MOXA DE-211 it simply doesn't work. If I plug the DE-211 in the RS-232 port of the newer machine, Ready is blinking which should mean there is a DHCP error, but it simply can't be. I have double checked, IP of the DE-211 is fix, but there is no conflict with other devices. If I don't plug it into the machine, it's working fine.
If I plug 2 of 3 from older machines into the DE-211 Ready is also blinking. There is only one older machine where Ready is not blinking plugged in, but the program transfer there is also not working.
If I understand correctly, the older machines control the whole process. Using the control panel of the machine we have to ask for a program nr stored on the PC and you can grab it if the custom software is running. Now if I plug the RS-232 out of the old MOXA gear and plug it into the DE-211 we're getting immediately an alarm on the machine. It seems the machine needs this custom software on the PC up and running to be able to communicate with it.
Is there no other way to send programs to the machines? It's okay if we must set the machine open to connections, but isn't it possible to simply send a program from the PC to the machine? Clear: it's absolutely not user friendly, but first I would like to understand what is happening, what should be happening, etc.
What protocol is used by the machine / PC to communicate? Do you have any experiences with a setup like this? Does the CNC program have to be a text file with the extension .mor and the content with % in the first and last lines and in the second line with prg nr. specified?
Thank you in advance!