Bob,
Okay, holding_cmd declared and initialized:
modbus_cmd_rd_hreg_t holding_cmd =
{
4000, //starting register
11 //Number of registers to read (Was 10)
};
Once initialized with the braces/set notation > {...} < you can change any/all
field(s) the way you like thenceforth with the > . < (member selection of an
object operator), but never with > {...} < again.
holding_cmd.start_addr=4100;
holding_cmd.num_reg=10;
Global-scope variables are all initialized with 0, if no other explicit
initializer is used.
{} (the empty set) initializes all fields of a structure with 0, even a
structure whose fields might be arrays, whatever the scope.
So, anywhere in your program you might have: modbus_cmd_rd_hreg_t holding_cmd =
{}; or simply holding_cmd = {}; if you may already have declared holding_cmd.
Best={1000};
Geraldo
--- In [email protected], "bobtransformer" <bobtransfor...@...> wrote:
>
> I am having a problem today...
>
> I can define this structure as global, above main() (or at the top of main()
> , and use it just fine in the code... But only once can I define it, it
> appears, or else I get this "expected an expression" error.
>
>
> modbus_cmd_rd_hreg_t holding_cmd =
> {
> 4000, //starting register
> 11 //Number of registers to read (Was 10)
> };
>
>
> where, modbus_cmd_rd_hreg_t itself is defined like this...
>
>
>
> typedef struct _modbus_cmd_rd_hreg_t
> {
> uint16_t start_addr;
> uint16_t num_reg;
> } modbus_cmd_rd_hreg_t;
>
>
>
> OK so far and the structure gets used in the program just fine.
>
> But when I want to re-define the values somewhere in main() so I can call the
> function that uses this structure, like this:
>
>
> holding_cmd =
> { //Error here "expected an expression"
> 4100,
> 10
> };
>
>
> I get the error on that line with the opening brace.
>
> Any ideas ??
>
> Thanks,
> boB
>
