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RS232 Command
Fn xxx.xxxxxxx
Pn N
Vn N
E x
C x
R
CLR
A x
S
QUE
M N
Vs N
Kp aa
I x
B aa[bb[cc[dd[ee[ff[gg]]]]]]
NOVATECH INSTRUMENTS
Table 2: Serial Commands
Set Frequency of output "n" in MHz to nearest 0.1 Hz. Decimal point required. Set
to 0.00 to turn off a channel. n=0, 1, 2, 3. Maximum setting: 171.1276031 MHz.
Single tone mode.
Set Phase of output "n". N is an integer from 0 to 16383. Phase is set to N*360
16384 or N*π/8192 radians. Sets the relative phase of the frequency output
depending upon the value of n=0, 1, 2, 3. Single tone mode.
Set voltage level of output "n". In default, the amplitude is set to the maximum:
approximately 1V
(+4dBm) into 50Ω. N can range from 0 (off) to 1023 (no
pp
decimal point allowed). Voltage level is scaled by N/1023. n=0, 1, 2, 3 to set the
amplitude on frequency 0, 1, 2 or 3. If N >=1024, the scaling is turned off and the
selected output is set to full scale.
Serial echo control. x=D for Echo Disable, x=E for Echo Enable
Select clock source. x=E for External clock, x=I for Internal Clock. May require
adjustment of Kp and the addition of external filtering of output. (Do not use this
command if the /R option is installed)
Reset. This command resets the 409B. EEPROM data is preserved and, if valid, is
used upon restart. This is the same as cycling power.
Clear. This command clears the EEPROM valid flag and restores all factory
default values.
x=E for LVCMOS Enable, x=D for LVCMOS Disable. (consult factory for
LVCMOS)
Saves current state into EEPROM and sets valid flag. State used as default upon
next power up or reset. Use the "CLR" command to return to default values.
Return present frequency, phase and status. Returns a character string of all inter-
nal settings.
Mode command. Mode '0' is single tone on all channels (default). If N=a, then the
phase is automatically cleared during each command; if N=n, then the phase is not
cleared (default). See Section 4.0 for details. See appendix for table mode.
Set the output Voltage scaling factor. N=1 for full scale, N=2 for one-half scale,
N=4 for one-quarter scale and N=8 for one-eighth scale. All channels are scaled
equally.
Set PLL reference multiplier constant. Must be one Hexadecimal byte as two
characters. Legal values are 1 (bypass PLL) and 4 to 20 (01
Kp times clock frequency must not be between 160MHz and 255MHz (for internal
clock, this disallows 5<=Kp<= 9). (see paragraph 4.12) Not used with /R option.
Set the I/O update pulse method. If x=a, then an I/O update is issued at the end of
each serial command (default). If x=m, then a manual I/O update pulse is sent by a
subsequent 'I p' command. (see section 4.0 for details)
This Byte command allows each register in the DDS chip to be set. Different
registers require a various number of bytes to be written depending upon the
function. Please consult the manual for details. Note that it is possible to set the
DDS chip into a non-functional mode, requiring a power cycle to recover. All
values are in hexadecimal and no error checking, other than correct format, is
performed.
4
Function
, 04
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409B Manual, 17-Apr-2015
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to 14
). Values of
h
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