Frequency of Multiple
Segment Waveforms
When two or four waveform segments make up the output waveform, the
waveform repetition frequency is 1/2 or 1/4 of the programmed frequency.
For example, if the RAM size is 8k, the waveforms in RAM 1 and RAM 2
comprise the output waveform. If the programmed frequency is 1 kHz, the
output frequency is 500 Hz. Similarly, if the RAM size is 16k, the
waveforms in RAM 0 through RAM 3 make up the output waveform. If the
programmed frequency is 1 kHz, the output frequency is 250 Hz. For 1 kHz,
you must either double or quadruple the programmed frequency.
Setting the Output
Attenuation
The maximum output voltage is +5.1175V / -5.12V into 50
Ω
.
The amplitude is controlled by the 12-bit output attenuator. The attenuation
value written to the AFG is based on the desired amplitude (volts peak) and
the output load:
Amplitude > + 0.51175 into 50
Ω
:
Atten = (Ampl / 5.1175) * 2047 (no attenuation)
Amplitude < + 0.51175 into 50
Ω
:
Atten = (Ampl / 0.51175) * 2047 (20 dB attenuation)
Amplitude > + 1.0235 into open circuit:
Atten = (Ampl / 10.235) * 2047 (no attenuation)
Amplitude < + 1.0235 into open circuit:
Atten = (Ampl / 1.0235) * 2047 (20 dB attenuation)
Atten is the attenuation value set from the Parameter Register and
Ampl
is
the desired output amplitude in volts peak.
Format
The attenuation is a two-byte parameter whose bits are defined in Table
C-2.
The attenuation value
(Atten)
is converted to the form:
A
1
*2
8
+A
2
As an example, to set 2 V
pk
into 50
Ω
:
Atten = (2 / 5.1175) * 2047
= 03 20
16
= 3 32
10
+ 128
= 131 32
10
byte 1 byte 2
128 is added to set bit 7, which turns the 20 dB attenuator off.
Appendix C
HP E1340A Register-Based Programming 245
Summary of Contents for E1340A
Page 12: ...Notes 12 HP E1340A Arbitrary Function Generator Module User s Manual ...
Page 14: ...14 HP E1340A Arbitrary Function Generator Module User s Manual ...
Page 42: ...Chapter 2 Generating Standard Waveforms with the HP E1340A 42 ...
Page 54: ...Chapter 2 Generating Standard Waveforms with the HP E1340A 54 ...
Page 58: ...Chapter 3 Generating Arbitrary Waveforms with the HP E1340A 58 ...
Page 84: ...Chapter 4 HP E1340A Sweeping and Frequency Shift Keying 84 ...
Page 130: ...Chapter 6 HP E1340A High Speed Operation 130 ...
Page 202: ...202 HP E1340A SCPI Conformance Information Chapter 7 ...
Page 218: ...218 HP E1340A Specifications Appendix A ...
Page 284: ...284 HP E1340A Register Based Programming Appendix C ...
Page 295: ...Index HP E1340A Arbitrary Function Generator User s Manual 295 ...