The FR-2053/2053T has 16-channel isolated photo coupler input, while the FR-2057/2057T has 16-channel isolated photo-coupler output. The default signal connector of FR-2053 and FR-2057 is a 20-pin header. The "T" stands for screw terminal connector and the "S" stands for 3-pin shroud connector. Each 3-pin connector has one Vcc pin, one ground and one signal pin. According to different applications, the users can choose suitable modules. The FR-2000 I/O module has an FRnet interface. The users can daisy chain several FR-2000 modules together. Via FRnet, the FR-2000 modules can extend the remote I/O control of PC, PAC and PLC easily. Further information about the networking of FR-2053/2057; refer to literature related to I-7188EF, I-8172, FRB-100/200/200U.