... -704M can be equipped with 6 modules on 6 sockets: M1, M2(MIO), M3(OUTP), ALM, AUX, and COMM ... . M1, M2 and M3 can be equipped with various input modules, ... ) Dimension(3)~(8) Symbols the module type installed on sockets ( M1,M2,M3,AL1,AL2,COMM): ModuleModule DescriptionsM1M2/MIOM3/OUTPAUXALMAUXCOMMNno module ...