This is done by typing SYNC or typing ASYNC while the desired port is currently selected.

Each channel may be set to SYNC or ASYNC independently of every other channel.

After first selecting the desired mode the user should select each of the ports which will be used and verify the correct settings for sync vs async.

If SYNC mode is selected, the DIU 2140 will provide both transmit clock and receive clock. The DIU 2140 will not accept an external clock and use that clock to time a T1 circuit. Also, in SYNC mode, if Request To Send (RTS) is not asserted by the DTE on pin 4 of the RS-232 interface, no data will be sent.

If your application requires Synchronous operation and your DTE is incapable of asserting RTS, please contact Verilink Tech Support @ (800) 837-4546 for assistance.

If ASYNC is selected the channel will support eight data bits, no parity and one stop bit. In ASYNC mode the state of RTS is ignored and all transmit data is sent.

The DIU 2140 does not convey control lead state changes from end to end. Applications which require toggling control leads will not operate over the DIU 2140.