Specifications

<C#>-60 V.3229 / V.3229L

synchronous Operating Commands

Serial Port Flow

Control

\Q Sets the type of flow control used by the serial

port. If the serial port speed exceeds that of the

modem connection, characters may be sent by the

DTE to the modem faster than it can send them to the

remote modem. The modem holds characters in an

internal buffer until they can be transmitted. When

this buffer is full the modem uses flow control to stop

data from DTE. As the modem continues to transmit

data and the buffer empties, flow control is again

used to cause the DTE to resume sending data.

AT\Q --\Q3 affect both DTE and DCE flow control.

AT\Q4 --\Q7 affect only flow control by the DCE.

AT\Q disables flow control.

When AT\Q1 is set, the modem generates and ac-

cepts XON/XOFF characters to start and stop the

data flow. These characters have the same parity as

the DTE setup taken from the last AT command.

AT\Q2 allows use of CTS off to stop the data from

the DTE and CTS on to restart it.

AT\Q3 forces the modem to act on CTS like \Q2. In

addition RTS on / off is used to facilitate starting and

stopping data from the modem to the DTE.

AT\Q4 disables flow control from the DCE.

AT\Q5 enables XON/XOFF flow control from the

DCE only.

AT\Q6 and \Q7 force the modem to use CTS like

\Q2 does but do not affect flow control by the DTE.