convert characters to string

how do i convert characters to string using a tsxscp114? i have read manuals but cant understand

it depends on system. the most common (standard) system is either
zero terminated strings (make array of characters followed by zero)
or for short strings (up to 255 characters) first byte is lenght
specifier and the rest are string elements.
As far as I know the later one is normally used in PLCs.
So if you want to make string with something like:
"Temperature is 22.3degC" you would just put them in array
with first byte being the string length (24).
Some PLCs have string data type, others use array of integers
but the principle is the same. Note that 16-bit registers are
holding two characters so your string would actually look like

18 54 where 18h is length (24dec), 54h is "T" etc.
65 6D "em"
70 65 "pe"
72 61 "ra"
74 75 "tu"
72 65 "re"
20 69 " i"
73 20 "s "
32 32 "22"
2E 33 ".3"
64 65 "de"
67 43 "gC"

Someone else might help you more as I have no experience with Modicon Micro PLCs...