R&S M3SR 4100 Series, Руководство по эксплуатации

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M3SR Series 4100 Selecting the Asynchronous Modem Operation Mode
4.142 Operating Manual 6175.4760.02 – 01
4.5.4.8 Selecting the Asynchronous Modem Operation Mode
Softkey Type Description
Listbox 1. Press 'Op Mode' softkey.
2. Select desired modem operation mode
from listbox.
3. Press 'ENT' to confirm. The new modem
operation mode is now effective.
Possible values:
• HiSp Async (high-speed asynchronous)
• standard asynchronous
By means of softkey Op Mode (Operation
Mode) the operator can adjust how the pay-
load will be formatted for the over the air trans-
mission.
The over-the-air payload data format is there-
fore not required to match the data format at
the asynchronous DTE (data terminal equip-
ment) interface. This sophisticated implemen-
tation enables the user to use asynchronous
DTE hardware like standard PCs and never-
theless increases the throughput by not trans-
mitting additional DTE start, stop or parity bits
over the air. Of course it is even possible to do
so for interoperability with legacy equipment.
There are two possible asynchronous opera-
tion modes, as follows:
Standard Asynchronous
The data format for the over the air payload
data is according to the adjusted data format
for the DTE interface (e.g. 8N1 = one start bit,
8 bit data, no parity, one stop bit).
This mode is useful for interoperability with
legacy modems, but reduces the total through-
put.
High-Speed Asynchronous
Additional start, parity and stop bits from the
DTE interface are stripped and not sent over
the air. Just the data bits from the DTE inter-
face are transmitted. This mode is more effi-
cient than Standard Asynchronous and is
interoperable with synchronously working leg-
acy modems.
This parameter is not adjustable when the
DTE interface is configured to work in syn-
chronous mode.