Please refer to the MULTAC Installation Guide attached below for details on multiple ATAC / M5000 / M5000X setups.
You will also find specification for cables in this document.
Symptoms: Couldn't detect any Mainframe:
Please check the fuse on the CPU board in the M5000 (fuse for the supply to the MULTAC).
Unplug the power cable,
Remove the top lid,
Locate the fuse (F1, 630mAT) near the Remote connector,
Check the fuse using a continuty tester (don't rely on visual check),
Replace the fuse if blown.