convert number to character

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Hi everyone,

I'm make a simple program using Igor to converting number to character then display the value on command window..
This is my Procedure/Function :
 #pragma rtGlobals=1        // Use modern global access method.
 
 
Function Test(ctrlName) : ButtonControl
    String ctrlName
    Variable a,b,c,d
String test,charA,charB,charC,charD
 
a=0x86
b=0x00
c=0x83
d=0x00
 
charA=num2char (a)
charB=num2char (b)
charC=num2char (c)
charD=num2char (d)
 
test= charA+charB+charC+charD
 
Print "test:",test
 
End


but i have some problem with my program. When I execute my function, I did not get a character for my 'charC'. This is the result that i got on the windows command : test: †

So can any of you help me slove this problem?
Hi randomz_raf,

the problem is that you are embedding ASCII 0, num2char(0x00), into your string. And this marks in C, and also for a few Igor functions, the end of the string. Therefore everything behind that is discarded.
Try
printf "%s,%s,%s", num2char(0x83), num2char(0x00), num2char(0x81)
printf "_%s_\r", num2char(0x83) + num2char(0x00) + num2char(0x83)

Here the first gives you the expected string, the second is cutoff at num2char(0x00).

Why do you want to insert ASCII 0 into a string in the first place?

April 20, 2011 at 05:41 am - Permalink

Dear thomas_braun,

Thank you for your reply. Actually I try writing my Igor program for my TDC Histogram. In my program I need to set null character for the four parameters (d,e,b,c) to initialize the TDC device. Then I will put the four parameters into one string (test) and use the string for as a buffer in my NI4882 ibwrt function.

 charA=num2char (a)
charB=num2char (b)
charC=num2char (c)
charD=num2char (d)
 
test= charA+charB+charC+charD
 
NI4882 ibwrt={ud,test,1}




So is it possible it will send the null (0 ASCII) to the device during ibwrt or it will set as end of string?

April 25, 2011 at 09:26 am - Permalink

 

 

[quote=randomz_raf]

charA=num2char (a)
NI4882 ibwrt={ud,test,1}



So is it possible it will send the null (0 ASCII) to the device during ibwrt or it will set as end of string?[/quote]

Yes, that should work because NI4882 ibwrt treats the string as a black box, not as a C string.

You could also use NIGPIBWriteBinary2.

You could also use NIGPIBWriteBinaryWave2:

 

 

Make/B/U test = {a,b,c,d}
NIGPIBWriteBinaryWave2 test

 

 

 

April 25, 2011 at 09:59 am - Permalink
Hi hrodstein,

Thank you for your help. Which one is much more better to use, NI4882 ibwrt or NIGPIBWriteBinary2?

April 25, 2011 at 10:11 am - Permalink
[quote]Which one is much more better to use, NI4882 ibwrt or NIGPIBWriteBinary2?[/quote]

It does not matter. I consider the NI488 operation to be low-level and I use the higher level operations when possible. I would tend to use NIGPIBWriteBinary2 for this situation.

April 25, 2011 at 02:26 pm - Permalink