Add check bison version in configure.ac file.
To build correctly matiec we need bison greater or equals than 2.4 version.
Now the "configure" script is able to check if system has correctly requirements.
FUNCTION WEIGH : WORD (* BCD encoded *)
VAR_INPUT (* "EN" input is used to indicate "scale ready" *)
weigh_command : BOOL;
gross_weight : WORD ; (* BCD encoded *)
tare_weight : INT ;
END_VAR
(* Function Body *)
IF weigh_command THEN
WEIGH := INT_TO_BCD (BCD_TO_INT(gross_weight) - tare_weight);
END_IF ;
END_FUNCTION (* Implicit "ENO" *)