Motorola V3229 Operating Instructions - Page 124

5 Asynchronous Operating Commands Serial Port Flow Control \Q \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 accepts 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. -60 V.3229 / V.3229L