3458A calram

[Alex Nikitin]

Apologies for a slight offtopic.

I've checked CALNUM on the HP3458A we've just received (bought used) and it is 54. The unit is supposed to be calibrated recently. Does that number look OK for quite an old meter?

Cheers

Alex

[alanambrose]

Hi Alex,

It's a bit hard to tell. You can figure a rough idea of the manufacturing date either from the date codes on the chips or the device serial number (maybe from the geller labs page).

Then either 90 day cals for a serious production device or annual cals for a non-critical lab device. (And since the earliest ship was ~89 that means at least some 90 day cals.) Bear in mind that the device generally gets more stable as time goes on anyway.

But 54 cals at say min $500 a pop means someone wanted the device kept up to spec.

Alan
 

[pelule]

Quote from: alanambrose on November 15, 2015, 05:01:59 AM


    And yes, I agree, it would be helpful to totally blank the display.

    Alan


This "problem" is solved already. See 3458A repair thread.

Simply send the command DISP OFF,'    ' to the 3458A.

Frank

I had the idea, to program the function key with that command, like I have done with the "TEMP?" function.
But I had no success yet and get error 106 String exceeds range
I used the command
DEFKEY 1, "DISP OFF, ' '"
The problem is to define the ".
Has anyone a good idea?
BR
PeLuLe

[Dr. Frank]

As described in the manual, that's not possible, if programming the function keys directly.
Quotation marks are not allowed in the DEFKEY command.

Maybe the intrinsic BASIC works.
As you can send that command via GPIB from an external program, this should also be possible with an internal program.
Therefore, you might first define a subprogram in nonvolatile RAM, just one line, which sends this command to the instrument.
Then you assign the call of this subroutine to the desired function key.

I never used the BASIC of the 3458A, but that might very probably do the job.

PS: That BASIC might also solve your running average problem. More tricky, though.
Frank

[Dr. Frank]

Bright idea   O0 .. works like a charm 
this TP procedure defines F1 for the call of the program, and also defines the single line sub routine.

procedure SET_F1_BLANK_HP3458;
begin
   clrscr;
   InitCEC;
   SetTimeOut(10000);
   cmd:= 'DEFKEY DEFAULT';     {clear F1 .. F9}
   sendstr(HP3458);
   cmd:= 'DEFKEY 1,"CALL DISP_BLANK"';   {call BASIC Program on F1}
   sendstr(HP3458);
   cmd:= 'SCRATCH';            {delete all BASIC elements from nvRAM}
   sendstr(HP3458);
   cmd:= 'SUB DISP_BLANK';               {start of subroutine}
   sendstr(HP3458);
   cmd:= 'DISP OFF,''   ''';             {single line of code...in that BASIC context, that's no direct command to 3458A }
   sendstr(HP3458);
   cmd:= 'SUBEND';                       {end of subroutine}
   sendstr(HP3458);

   Goto_Local(HP3458);
   EndCEC;
 end;

Frank

[TiN]

Python-snake version:

# Python Display-off F7 key define GPIB app
# http://xdevs.com/fix/hp3458a/
import sys
import Gpib

inst = Gpib.Gpib(0,3) # Instrument GPIB Address = 3
inst.clear()
inst.write("DEFKEY 7,\"CALL DISP_BLANK\"")
inst.write("SCRATCH")
inst.write("SUB DISP_BLANK")
inst.write("DISP OFF,\"  \"")
inst.write("SUBEND")

Programms only F7, as I already had some other macros on other buttons.

[pelule]

I used a "quick&dirty" way. It may of interrest for others, not able to program.
I used the Agilnt USB-to-GPIB clone with installed Agilent Commuication Libraries and entered thme in interactive GPIB command tool.
Entered the following commands (defined F0 key):
   END ALWAYS
   DEFKEY 0,"CALL DISP_BLANK"
   SCRATCH
   SUB DISP_BLANK
   DISP OFF,"
   SUBEND

Note: DISP OFF," is the short form of DISP OFF," "

[texaspyro]

Now, it would be useful to try and get MWRITE working. This guy seems to have made some progress at least:

I wrote the HP3458A program (based upon the excellent work that PHK did) that John (ke5fx) includes in his GPIB Toolkit package.

I wanted to add a calram restore capability, but, as PHK discovered,  writing to the cal ram is protected by several different mechanisms and you have to call some internal subroutines to get write access.  This subroutines are in different locations depending upon the firmware.  Writing a general purpose tool to do that would be a big problem...

[bingo600]

I wrote the HP3458A program (based upon the excellent work that PHK did) that John (ke5fx) includes in his GPIB Toolkit package.

Hi texaspyro   

Wanna play along , or is "The Lady" still taking your time ?? .. Maybe she should be in the image
https://www.eevblog.com/forum/metrology/raspberry-pi23-logging-platform-for-voltnuts/

/Bingo

[dr.diesel]

Unknown history on my unit.  Looks like someone has replaced U121 and U122, wonder why they left U132?

[TheSteve]

They did the bare minimum to get it to pass the self test. The main memory nvrams do seem to die before the Cal nvram. They also may not have a programmer to read/write the nvram. No matter the reason you will want to swap it out.

[dr.diesel]

No matter the reason you will want to swap it out.

Yup!  Just saved the data via the Linux utility that bingo600 provided above, thank you Sir.  A new DS1220AD-150+ will be added to my next DK order.

[bingo600]

Yup!  Just saved the data via the Linux utility that bingo600 provided above, thank you Sir.  A new DS1220AD-150+ will be added to my next DK order.

You're welcome 

Actually i ought to replace all 3 in my 58' too

/Bingo

[texaspyro]

Hi texaspyro   

Wanna play along , or is "The Lady" still taking your time ?? .. Maybe she should be in the image

I've hacked up Lady Heather lots of times to do logging/plotting and instrument control.  It provides a nice base of capabilities and now runs on Windows, Linux, macOS, and FreeBSD.  Heather's plotting, logging, and drawing routines are fairly generic.  So are the keyboard menu routines once you figure out how they work (lotsa luck with that).

For instance, if you dig through the source code you will find references to "luxor" which is my LED / power analyzer / swiss army knife device. 

I've been looking at prasimix's SCPI power supply...  Heather knows about SCPI... 

V 5.0 added support for writing/reading log files in XML format besides the standard  simple ASCII logs. It's fairly easy to add new data types to.

I just added support for allowing up to 10 external com links (serial/USB or TCP/IP).  Makes it easy to talk to things in addition to a GPSDO... Time interval counter, anyone?

[mimmus78]

I have defined a key for this. You don't need quote if you are not displaying any message, so just this will do:

  DISP MSG,

and yes you can do this by just the front panel.