Squarewave, generated by Clock Synthesis has 4-digit resolution for both frequency and period
entry but the hardware is still programmed in terms of frequency and the same differences may
occur in switching the display from period to frequency and back to period.
Turning the rotary control will increment or decrement the numeric value in steps determined by
the position of the edit cursor (flashing underline); the cursor is moved with the left and right
arrowed cursor keys.
Note that the upper frequency limits vary for the different waveform types; refer to the
Specifications section for details.
Frequency setting for arbitrary, sequence pulse and pulse-train is explained in the relevant
sections.
Amplitude
AMPLITUDE:
+20·0 Vpp
♦
Vpp Vrms
◊
◊
dBm load:hiZ
◊
Pressing the AMPL key gives the
AMPLITUDE
screen.
The waveform amplitude can be set in terms of peak-to-peak Volts (Vpp), r.m.s. Volts (Vrms) or
dBm (referenced to a 50
Ω
or 600
Ω
load). For Vpp and Vrms the level can be set assuming that
the output is open-circuit (
load:hiZ
) or terminated (
load:50
Ω
or
load:600
Ω
); when dBm is
selected termination is always assumed and the
load:hiZ
setting is automatically changed to
load:50
Ω
. Note that the actual generator output impedance is always 50
Ω
; the displayed
amplitude values for 600
Ω
termination take this into account.
With the appropriate form of the amplitude selected (indicated by the filled diamond) the
amplitude can be entered directly from the keyboard in integer, floating point or exponential
format, e.g. 250mV can be entered as ·250 or 250 exp -3, etc., However, the display will always
show the entry in the most appropriate engineering units, in this case 250mV.
Turning the rotary control will increment or decrement the numeric value in steps determined by
the position of the edit cursor (flashing underline); the cursor is moved with the left and right
arrowed cursor keys.
Alternate presses of the ± key will invert the MAIN OUT output; if DC OFFSET is non-zero, the
signal is inverted about the same offset. The exception to this is if the amplitude is specified in
dBm; since low level signals are specified in -dBm (0dBm = 1mW into 50
Ω
= 224mVrms) the
-
sign is interpreted as part of a new amplitude entry and not as a command to invert the signal.
Note that for DC, sinx/x, pulse train, arbitrary and sequence amplitude can only be displayed and
entered in the Vpp form; further limitations on pulse-train, arbitrary and sequence amplitude are
discussed in the appropriate sections.
DC Offset
DC OFFSET:
p0·00 mVdc
(0·00 mVdc)
load:hiZ
◊
Pressing the OFFSET key gives the
DC OFFSET
screen. The offset can be entered directly
from the keyboard in integer, floating point or exponential format, e.g. 100mV can be entered as
·1 or 100 exp -3 etc. However, the display will always show the entry in the most appropriate
engineering units, in this case 100mV. During a new offset entry the ± key can be used at any
time to set the offset negative; alternate presses toggle the sign b and -.
22