iconv(): Detected an illegal character in input string - php

Question

I am using Iconv function to convert string to requested character encoding. Look On Below Code
$sms_text = 'A:'f3*'F'; // Output received from SMPP
$result = iconv('UTF-16BE' ,'UTF-8//IGNORE' , $sms_text);
echo 'Ignore: ' .$result;
echo $sms_text = iconv('UTF-16BE' ,'UTF-8' , $sms_text);
$result1 = iconv('UTF-16BE' ,'UTF-8//TRANSLIT' , $sms_text); //line no (53)
echo 'Transilt: '.$result1;
And I received the below Output
If I have a string of dari and pashto Language, then its showing only first word and dont return remaining string after blank space. Even //IGNORE gives the same output.
Should I replace these blank spaces with the help of with some other character so that I can get complete string?
Note: I am passing string received from SMPP(receiver).
SMS Sent to SMPP : افغانستان کابل
Outpur Received from SMPP : 'A:'f3*'F
String back converted by iconv : افغانستان
English string is working well.
Thanks in advance.

Answer 1

You are converting string to UTF-8 charset on this line:
echo $sms_text = iconv('UTF-16BE' ,'UTF-8' , $sms_text);
The error appears becouse you are trying to convert it second time.
To resolve this issue you should not update $sms_text variable on mentioned line.
Here is a code and output that works for me:
$sms_text ="فغانستان کابل";
echo "UTF-8 : $sms_text \n";
$sms_text = iconv('UTF-8', 'UTF-16BE', $sms_text);
echo "UTF-16BE : $sms_text \n";
echo 'Ignore: ' . iconv('UTF-16BE' ,'UTF-8//IGNORE' , $sms_text) . "\n";
echo 'Simple: ' . iconv('UTF-16BE' ,'UTF-8' , $sms_text) . "\n";
echo 'Transilt: '. iconv('UTF-16BE' ,'UTF-8//TRANSLIT' , $sms_text) . "\n";
Output:
UTF-8 : فغانستان کابل
UTF-16BE : A:'F3*'F
Ignore: فغانستان کابل
Simple: فغانستان کابل
Transilt: فغانستان کابل
As for blank spaces, could you please share the test string?