... (Option) FTR-01H 16/321, 8 Analogue input channels of mutual AC/DC (4 channels per group), one adapter for one group.2 ... , 4 AC voltage input channels of: 130V,130V,130V,260V,3, 4 AC current input channels ... required FTR-01H 16/641, 8 Analogue input channels of mutual AC/DC (4 channels per group), one adapter for one group.2 ...