I switched the cables for the PSL table temperature signals, H1:PSL-ENV_LASERRM_TBLS_TEMP_DEGF (table south) and H1:PSL-ENV_LASERRM_TBLN_TEMP_DEGF
(table north) at the back of the PSL environmental chassis.  This corrects the north/south identity problem.  So now the signal labelled TBLN
really is the "north" end of the table, as per the documentation.