HP FET MULTIPLEXER E1351A/53A manual Register-Based Programming for Maximum Speed

Register-Based Programming for Maximum Speed

This is an outline of the algorithm that needs to be followed to have the HP E1326B 51¤2 Digit Multimeter do high-speed scanning using the 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	dcv
set the range	1V

Note: You must have a fixed range to do 13k. Auto range will do 2.5k.

set the aperture10 msec

Note: This will cause readings to be returned as 16 bits.

set the auto zero	off or once
set offset Compensation	off
set trigger source	Immediate
set trigger count	1
set trigger delay	0
set Sample Count	16

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	Timer
This is the time between A/D readings.
set sample Period	76ms

76 msec is the minimum or fastest A/D time.

set trigger arm armed

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.

Appendix B HP E1351A/53A Register-Based Programming 93