VXI 3002 - Manual (Page 40)

3-10
Modulation mode
These commands allow you to select the modulation mode between amplitude, frequency and
phase modulation as well as binary (2-level) and quadrature (4-level) frequency shift keying.
Binary FSK results from a logic level digital signal applied to the TRIGGER INPUT socket.
Quadrature FSK is achieved using both the TRIGGER INPUT and PULSE INPUT sockets. Also
pulse modulation may be selected from a signal connected to the PULSE INPUT socket. These
modulations may be used in the combinations shown in the table below. Additionally, an external
signal applied to the EXT MOD INPUT socket can be combined with any selected modulation
combination.
MODE Set modulation mode
Data type : Character Program Data (valid combinations of AM, FM, PM, FSK2L,
FSK4L or PULSE. See table below.)
Allowed suffices : None
Default suffix : None
Examples: MODE AM,FM
MODE FM,PULSE
VALID MODE COMBINATIONS TABLE
AM [,PULSE]
FM [,PULSE]
PM [,PULSE]
AM,FM [,PULSE]
AM,PM [,PULSE]
FSK2L [,PULSE]
FSK4L
Note...
Order is not important, for example AM,FM is equivalent to
FM,AM. PULSE modulation can be used with any of the
AM,FM,PM and FSK2L modes, but not with FSK4L.
FSK2L and FSK4L parameters are controlled using the FM
commands. The frequency shifts produced by the applied data
are as follows:
2FSK 4FSK
TRIGGER SHIFT TRIGGER PULSE SHIFT
1 +D 1 0 +D
0 −D 1 1 +D/3
0 1 −D/3
0 0 −D
Where D is the set deviation value.
MODE? Prepares message containing information on Modulation Mode in the
following format:
:MODE <mode>
where: <mode> is character program data indicating the modulation
mode settings
Example: :MODE AM,FM