Short name: Flow Cntrl
Requires: Base Development System
Classes: Instr, Serial Instr
Specifies the flow control method used for both transmitting and receiving data. Valid values include: (0) Flow None, (1) Flow XON/XOFF, (2) Flow RTS/CTS, (3) Flow XON/XOFF and RTS/CTS, (4) Flow DTR/DSR, (5) Flow XON/XOFF and DTR/DSR. Certain values or combinations of values may not be supported by all serial ports and/or operating systems.
(0) None�Does not use flow control, and buffers on both sides of the connection are assumed to be large enough to hold all data transferred.
(1) XON/XOFF�Uses the XON and XOFF characters to perform flow control. The transfer mechanism controls input flow by sending XOFF when the low-level I/O receive buffer is nearly full, and it controls the output flow by suspending transmission when XOFF is received.
(2) RTS/CTS�Uses the RTS output signal and the CTS input signal to perform flow control. The transfer mechanism controls input flow by unasserting the RTS signal when the low-level I/O receive buffer is nearly full, and it controls output flow by suspending the transmission when the CTS signal is unasserted.
(3) XON/XOFF and RTS/CTS�Uses both values 1 & 2.
(4) DTR/DSR�Uses the DTR output signal and the DSR input signal to perform flow control. The transfer mechanism controls input flow by unasserting the DTR signal when the low-level I/O receive buffer is nearly full, and it controls output flow by suspending the transmission when the DSR signal is unasserted.
(5) XON/XOFF and DTR/DSR�Uses both values 4 & 5.
| 0 | None | 
| 1 | XON/XOFF | 
| 2 | RTS/CTS | 
| 3 | XON/XOFF & RTS/CTS | 
| 4 | DTR/DSR | 
| 5 | XON/XOFF & DTR/DSR | 
The following table lists the characteristics of this property.
| Data type | ![]()  | 
| Permissions | Read/Write |