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User Manual (1.0.14) EasyVR 3 25
Arguments Mapping
Command or status messages sent over the serial link may have one or more numerical arguments in the
range -1 to 31, which are encoded using mostly characters in the range of uppercase letters. These are
some useful constants to handle arguments easily:
ARG_MIN
'@' (40h)
Minimum argument value (-1)
ARG_MAX
'`' (60h)
Maximum argument value (+31)
ARG_ZERO
'A' (41h)
Zero argument value (0)
ARG_ACK
' ' (20h)
Read more status arguments
Having those constants defined in your code can simplify the validity checks and the encoding/decoding
process. For example (in pseudo-code):
# encode value 5
FIVE = 5 + ARG_ZERO
# decode value 5
FIVE – ARG_ZERO = 5
# validity check
IF ARG < ARG_MIN OR ARG > ARG_MAX THEN ERROR
Just to make things clearer, here is a table showing how the argument mapping works:
ASCII
@
A
B
C
...
Y
Z
^
[
\
]
_
`
HEX
40
41
42
43
...
59
5A
5B
5C
5D
5E
5F
60
Value
-1
0
1
2
...
24
25
26
27
28
29
30
31