IDCommon_ivu23_2.8m_v2 Nomenclature / Abbreviations TD : M1 X1 Top Downstream TU : M2 X2 Top Upstream BD : M3 X3 Bottom Downstream BU : M4 X4 Bottom Upstream Errors noticed Schemtic rev3 claims #2 home flag is J4-12. This is inconsistent with PMC M-variable mapping. Schematic likely wrong, check wiring.