User`s manual
Loading the DAC from the VXIbus
This section shows how to load waveform data into the AFG’s DAC
directly from the VXIbus backplane. For additional information on loading
the DAC directly, refer to Chapter 7.
The High Speed Data
Register
Waveform data from the VXIbus is loaded into the DAC via the following
register.
• High-Speed Data Register:
base_addr + 26
16
Address 1514131211109876543210
base + 26
16
DAC code unused
DAC Code: The DAC code is a 13-bit signed (2’s complement) or
unsigned number. With
[SOURce:]VOLTage[:LEVel][:IMMediate][:AMPLitude] set to 5.12 V and a
matched output load, the least significant bit (LSB) is 1.25 mV.
BASIC Program Example (VXISRCE)
The program uses the V360 Controller to download the data using the
VXIbus instead of transferring it directly to the AFG using GPIB.
1 !RE-STORE"VXISRCE"
2 !This program uses the V/360 embedded controller to send waveform
3 !data directly to the AFG dac over the VXIbus backplane.
4 !
10 !Assign I/O path between the computer and E1445A.
20 ASSIGN @Afg TO 1680
30 COM @Afg,Addr
40 !
50 !Call the subprograms which reset the AFG and determine the base
60 !address of the registers in A24 address space.
70 CALL Rst
80 CALL A24_offset
90 !
100 !Scale the amplitude, set the dac data format and dac data source.
110 OUTPUT @Afg;"SOUR:VOLT:LEV:IMM:AMPL 5.11875V" !amplitude
120 OUTPUT @Afg;"SOUR:ARB:DAC:FORM SIGN" !dac data format (signed)
130 OUTPUT @Afg;"SOUR:ARB:DAC:SOUR VXI" !dac data source
140 OUTPUT @Afg;"*OPC?" !Wait for the SCPI commands to complete
150 ENTER @Afg;Complete
160 !
170 !Call the subprogram which sends data directly to the dac.
Continued on Next Page
506 Register-Based Programming Appendix C