I just got an HL-1060 100W EBay laser cutter, and it has an RDC6442S-B(EC) controller. The only manual or information I can find is on the RDC6442G (including on Ruida’s site). The seller and manufacturer sites also just have the “G” manual.
From the RDC6442G’s manual the last few letters describe the type of interface panel, but there’s nothing about what “S-B(EC)” means.
I’m pretty sure even the G version has dual outputs (mine does). S supposedly stands for “standalone”, but I’ve never heard a definitive answer for what that means. I know my G and S behave slightly differently with the way the user origin works, but that’s all I’ve noticed.