Register-Based Programming For Maximum Speed - HP E1351A User Manual

Register-Based Programming for Maximum Speed

Appendix B
This is an outline of the algorithm that needs to be followed to have the
⁄
HP E1326B 5 1 Digit Multimeter do high-speed scanning using the
2
HP E1351A 16-Channel FET Multiplexer. This procedure programs
the multimeter and downloads a scan list to the FET multiplexer so the
hardware controls the entire scanning process. The HP E1326B has several
things that should be understood when doing register programming.
1. Table B-1 on page 96 lists the multimeter's commands. When doing
any of these commands, you are writing to registers which are read by the
multimeter's voltmeter microprocessor. It is important to follow the
procedure in Figure B-3 on page 97 on how to send commands. This will
enable you to handshake with the E1326B microprocessor as you can easily
write commands faster than the processor can execute them.
2. In order to program the HP E1326B Multimeter to take readings with
the HP E1351A FET Multiplexer at its highest speed, do the commands
from Table B-1 on page 96. Note that all values in Table B-1 are specified
in decimal.
set the function
set the range
Note: You must have a fixed range to do 13k. Auto range will do 2.5k .
set the aperture
Note: This will cause readings to be returned as 16 bits.
set the auto zero
set offset Compensation
set trigger source
set trigger count
set trigger delay
set Sample Count
This should be the total number of A/D readings that you will take
(for example, once through a 16 channel list = 16, 10 times through
a 16 channel list = 160).
set sample Source
This is the time between A/D readings.
set sample Period
76 µsec is the minimum or fastest A/D time.
set trigger arm
This arms the DVM to take all of the reading specified above.
Do not execute the next command yet. You still need to set the scan list in
the HP E1351A. Trigger immediate will start everything.
3. Now download the channel list to the HP E1351A
•
Set CLR SCN in Scan Control Register to one, then back to zero in
order to clear the previous scan list.
•
DIR in the Status/Control Register set to false.
HP E1351A/53A Register-Based Programming 93
dcv
1V
10 µsec
off or once
off
Immediate
1
0
16
Timer
76µs
armed