AT&K Flow Control
The &K command enables you to select the type of flow control used between your modem and the local computer when asynchronous mode is selected.You may want to do this to prevent possible data loss resulting from buffer overflow.
Using flow control guarantees that data buffers in your modem and computer won’t overflow.Your modem and your terminal or computer must be using the same type of flow control.
☞Flow control is only available when your modem is configured for constant speed mode or reliable or
Flow control will be ignored when your modem is configured for variable speed mode (AT\N1) or is in local command state.
WARNING
XON/XOFF flow control must not be selected when you are using XModem, YModem and SEAlink file transfers. XON/XOFF flow interferes with the operation of these file transfer protocols and will cause unreliable operation.
Options
AT&K0 | Flow control disabled |
AT&K3 ■ | RTS/CTS (hardware) flow control |
| The modem and computer use the CTS (Clear to Send) and RTS (Request to |
| Send) signals on the |
AT&K4 | XON/XOFF (software) flow control |
| The modem and computer use the XON and XOFF characters (DC1 and |
| DC3) to control the flow of data. |
AT&K5 | Transparent XON/XOFF flow control |
| The modem and computer encode and decode XON and XOFF characters |
| which are part of the data stream. |
| Transparent XON/XOFF provides reliable operation when using file transfer |
| protocols. |
AT&K9 | Failsafe flow control |
| When the modem’s data buffer approaches maximum capacity, the modem |
| will lower the CTS signal. If the computer subsequently sends more than 60 |
| (S82) characters to the modem, the modem will send an XOFF character to |
| the computer. |
| When the modem is ready to accept more data from the computer it will |
| assert CTS and, if an XOFF was sent by the modem, will send an XON |
| character to the computer. |
| Failsafe flow control only affects data being transmitted from the computer |
| to the modem. Flow control is not supported for data being transmitted by |
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