101BExtended instructions
8.2 String and character
S7-1200 Programmable controller
252
System Manual, 11/2011, A5E02486680-05
The IN and OUT parameters specify byte arrays and not hexadecimal String data. ASCII
characters are converted and placed in the hexadecimal output in the same order as they
are read. If there are an odd number of ASCII characters, then zeros are put in the right-
most nibble of the last converted hexadecimal digit.
Table 8- 44 ATH condition codes
RET_VAL (W#16#....)
Description
ENO
0000
No error
TRUE
0007
Invalid ATH input character
FALSE
Table 8- 45 Examples of ASCII-to-hexadecimal (ATH) conversion
IN character bytes
N
OUT value
ENO
'0123'
4
W#16#0123
TRUE
'123AFx1a23'
10
DW#16#123AF01023
FALSE
'a23'
3
W#16#A230
TRUE
Table 8- 46 HTA instruction
LAD / FBD
SCL
Description
ret_val := HTA(
in:=_variant_in_,
n:=_uint_in_,
out=>_variant_out_);
Converts packed hexadecimal digits to their corresponding ASCII
character bytes.
Table 8- 47 Data types for the HTA instruction
Parameter and type
Data Type
Description
IN
IN
Variant
Pointer to input byte array
N
IN
UInt
Number of bytes to convert (each input byte has two 4-bit nibbles and
produces 2N ASCII characters)
RET_VAL
OUT
Word
Execution condition code
OUT
OUT
Variant
Pointer to ASCII character byte array
Conversion begins at the location specified by parameter IN and continues for N bytes. Each
4-bit nibble converts to a single 8-bit ASCII character and produces 2N ASCII character
bytes of output. All 2N bytes of the output are written as ASCII characters 0 to 9 through
uppercase A to F. The parameter OUT specifies a byte array and not a string.
Each nibble of the hexadecimal byte is converted into a character in the same order as they
are read in (left-most nibble of a hexadecimal digit is converted first, followed by the right-
most nibble of that same byte).
