| External Interfaces/API |     ![]()  | 
Using Control Pins
As described in Serial Port Signals and Pin Assignments, 9-pin serial ports include six control pins. These control pins allow you to:
The properties associated with the serial port control pins are given below.
| Property Name | 
Description | 
DataTerminalReady | 
Specify the state of the DTR pin | 
FlowControl | 
Specify the data flow control method to use | 
PinStatus | 
Indicate the state of the CD, CTS, DSR, and RI pins | 
RequestToSend | 
Specify the state of the RTS pin | 
   | Example: Using Events and Callbacks | Signaling the Presence of Connected Devices | ![]()  |