User`s manual

8 Serial Port I/O

8-58

Write the ata command to the second modem. This command puts the modem

in “answer mode,” which forces it to connect to the first modem.

fprintf(s2,'ata')

After the two modems negotiate their connection, you can verify the connection

status by examining the value of the Carrier Detect pin using the

PinStatus

property.

s1.PinStatus

ans =

CarrierDetect: 'on'

ClearToSend: 'on'

DataSetReady: 'on'

RingIndicator: 'off'

You can also verify the modem-modem connection by reading the descriptive

message returned by the second modem.

s2.BytesAvailable

ans =

out = fread(s2,25);

char(out)'

ans =

ata

CONNECT 2400/NONE

Now break the connection between the two modems by configuring the

DataTerminalReady property to off. You can verify that the modems are

disconnected by examining the Carrier Detect pin value.

s1.DataTerminalReady = 'off';

s1.PinStatus

ans =

CarrierDetect: 'off'

ClearToSend: 'on'

DataSetReady: 'on'

RingIndicator: 'off'

5. Disconnect and clean up – Disconnect the objects from the modems, and

remove the objects from memory and from the MATLAB workspace.