3Com U.S. Robotics 56K Voice, Справочник по командам

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14-10 C
HAPTER
14: T
ESTING THE
C
ONNECTION
Testing Using
Keyboard Data
(ATS16=8)
1 Send
AT&M0&N3S14.0=0
to prepare the Business Modem for testing.
This command disables error control, fixes the connection rate at 2400
bps, and makes the Business Modem return to command mode when
you type the escape code (
+++
).
2 Establish a connection with the remote device.
3 If you haven't already done so, arrange with the remote user to
cooperate with the test.
If necessary, set the remote device to acknowledge the remote digital
loopback request. 3Com modems should be set to &T4. (Older 3Com
modems should be set to S16=8.)
4 Send the Business Modem
ATS16=8O
.
The Business Modem enters remote digital loopback mode and then goes
back online (O command). It then transmits the test signals, causing the
remote device to enter remote digital loopback mode. The MR status
light flashes during this operation.
5 Type a short message. It will be looped back to your Business Modem by
the remote device and to your screen for verification. (The remote user
will not see your data.)
6 Send the escape code,
+++
, and then
ATS16=0
to end the test.
If you issue an invalid command, the Business Modem sends an ERROR
message. If you set Register S18, the Business Modem automatically ends
the test when the test timeout is reached. See the example in the
previous section,
Stopping a Test for an example of using S18.
If you wish to resume data transmission with the remote device, add the
O command (ATO) after the
ATS16=0
string to return online. If you do
this, remember that error control is disabled. Because error control is
negotiated during the connection sequence, its status cannot be changed
until the Business Modem is back on hook and in Command mode.
7 Send
AT&M4
, unless you used a reset command (ATZ or ATZ!
)
.