Sa, Relay Pcb; Optional I/F - Citizen CL-S6621 Technical Manual

(b) Fan driver
This is a fan drive circuit. The fan is used to cool both "SA Ribbon Motor F" and "SA
Ribbon Motor R". When the temperature of the "SA Ribbon Motor F" exceeds a certain
value, the fan starts to rotate.

(8) SA, Relay PCB

Relays the signals between the "SA, Main PCB" and an optional I/F board.

(9) Optional I/F

(a) Parallel I/F (IEEE1284) (Option)
This is the parallel I/F to transmit and receive parallel data between the printer and the host.
It supports Centronics Compatible mode, NIBBLE mode and ECP mode.
Parallel I/F, serial I/F, or USB I/F is automatically selected when data is received.
(b) Wired LAN I/F (Option)
This is a circuit which supports Ethernet protocol. LAN connection is possible.
(c) Wireless LAN I/F (Option)
This is a circuit which supports wireless LAN protocol (IEEE802.11n/IEEE802.11g/
EEE802.11b).
2-21
Operation of Control Parts
CL-S6621