Serial Port (Core, I/O Frame, I/O-22)

The Properties listed below are specific to the RS-232 Serial Port component. The other Properties available when the RS-232 Serial Port is selected are related to the Core, I/O Frame, or the I/O-22 Status topics. See Status (Core), Status (I/O Frame), and Status (I/O-22).

Property	Function	Choices
Name	Text name identifying the RS-232 Serial Port component.	User defined
Serial Port	Identifies which serial port you are communicating through.	0 to 4

Control	Function	Default / Range
TX Bytes	Displays a running total of the number of bytes sent.	N / A
RX Bytes	Displays a running total of the number of bytes received.	N / A
Reset	Resets both TX Bytes and RX Bytes to zero.	N / A

The available Control Pins depend on settings in Properties.

Pin Name	Value	String	Position	Pins Available
Reset	Trigger			Input/Output
Receive Bytes	Text Box			Output
Transmit Bytes	Text Box			Output

Pinout

• Pin 2 - RX (Receive)
• Pin 3 - TX (Transmit)
• Pin 5 - GND (Signal Ground)
• All other pins on a Core are not supported
• Pin 4 on an I/O-22 provides +5.5VDC @ 70mA (not on any other Q-SYS product, though)

This signal to DE-9 configuration is known as DTE. All 9-pin D-Shell RS-232 pinned as DTE have this configuration. All PC serial ports are DTE as is the Core, I/O-Frame and I/O-22. Usually peripherals are DCE, which reverses the receive and transmit pins, allowing a straight-thru cable to be used.

You must check the pinout of any equipment, including the cable, to be connected to a Q-SYS serial port for input or output. Many times in serial troubleshooting, problems may be solved by inserting a "null-modem" adapter or cable to swap the TX and RX pin positions. For custom terminated DE-9 connectors, pins 2 and 3 may need to be swapped on one end of the cable. In any case, a TX pin on one end MUST be connected to an RX pin on the other and vise-versa for data to flow properly.