14
QIO-S4 Serial Port Pinouts
The QIO-S4 features four serial ports:
• COM 1 is configurable in Q-SYS Designer Software for RS232, RS485 Half Duplex TX, RS485 Half Duplex RX, or
RS485/422 Full Duplex.
• COM 2-4 ports are dedicated to RS232 communication.
RS232 Pinout: COM 1 (Configurable), COM 2-4 (Dedicated)
Pin
Signal Flow
Description
N/A
Signal ground
TX
Output
Transmit data
RX
Input
Receive data
RTS
Output
Ready to Send1
CTS
Input
1 When using hardware flow control.
RS485 Half Duplex TX or RX Pinout: COM 1 (Configurable)
Pin
Signal Flow
Description
N/A
Signal ground
TX
Input/Output
Differential B-
RX
(Unused)
(Unused)
RTS
Input/Output
Differential A+
CTS
(Unused)
(Unused)
RS485/422 Full Duplex: COM 1 (Configurable)
Pin
Signal Flow
Description
N/A
Signal ground
TX
Output
Differential Z- / Tx-
RX
Input
Differential A+ / Rx+
RTS
Output
Differential Y+ / Tx+
CTS
Input
Differential B- / Rx-