Can I connect multiple expanders at once?

You can connect one PPEXP1 or PPEXPX2 and one AXON-1 or AXON-2 at the same time. You can't connect multiple AXONs or PPEXPs at the same time however.

Also make sure the expanders are connected to the right port. Serious damage can be done to the module by plugging an expander into the wrong port! See the Pam manual for further details.