OMRON CV500 series PLC has a variety of modules

OMRON
SYSMAC LINK Unit
CV500-SLK11

CV500-SL CPU Bus Unit for Com SYSMAC LINK Unit SYSMAC LINK Unit (optical) CV500-SLK11.

OMRON
Remote I/O Master Unit
CV500-RM211

CV500-RM SYSMAC BUS Remote I/O Master Unit (optical) CV500-RM211. Light type.

OMRON
Remote I/O Master Unit
CV500-RM221

CV500-RM SYSMAC BUS Remote I/O Master Unit Wired CV500-RM221. Wire Type.

OMRON
Remote I/O Master Unit
CV500-RT211

CV500-RT SYSMAC BUS Remote I/O Slave Unit (optical) CV500-RT211. Light type.

OMRON
Remote I/O Master Unit
CV500-RT221

CV500-RT SYSMAC BUS Remote I/O Slave Unit (wired) CV500-RT221. Wire Type.

OMRON
Ethernet Unit
CV500-ETN01

CV500-ET CPU Bus Unit for Com Ethernet Unit CV Series Only CV500-ETN01. 10BASE-5 type.

OMRON
BASIC Unit
CV500-BSC11

CV500-BS CPU Bus Unit BASIC Unit CV500-BSC11. RS-232C: 2 ports, RS-422: 1 port.

OMRON
BASIC Unit
CV500-BSC21

CV500-BS CPU Bus Unit BASIC Unit CV500-BSC21 RS-232C: 2 ports, RS-422: 1 port.

OMRON
BASIC Unit
CV500-BSC31

CV500-BS CPU Bus Unit BASIC Unit CV500-BSC31. RS-232C: 2 ports. Centronics: 1 port.

OMRON
BASIC Unit
CV500-BSC41

CV500-BS CPU Bus Unit BASIC Unit CV500-BSC41. RS-232C: 2 ports. Centronics: 1 port.

OMRON
BASIC Unit
CV500-BSC51

CV500-BS CPU Bus Unit BASIC Unit CV500-BSC51. RS-232C: 1 port. GP-IB: 1 port.

OMRON
BASIC Unit
CV500-BSC61

CV500-BS CPU Bus Unit BASIC Unit CV500-BSC61. RS-232C: 1 port. GP-IB: 1 port.