| cyg_mbop_read_id | ||
|---|---|---|
 | 111.5. Backend Interface |  |
Name
cyg_mbop_read_id — Return specific extended device ID
Synopsis
#include <cyg/modbus.h>
Cyg_ErrNo cyg_mbop_read_id(void *private, cyg_uint8 objectid, cyg_uint8 *nextid, cyg_uint8 *len, cyg_uint8 *buffer);
Description
This function does not provide a response, but purely supplies
“Extended” ObjectID data to the common
MEI Type 14 request handler.
The objectid parameter specifies the object to
be returned. The caller supplies an optional data buffer pointer in
the buffer parameter, with the value referenced
by the len pointer being the space available in
the buffer. If the objectid is supported then
the buffer is filled, and len is updated with
the actual length of the object. The use of
a NULL buffer allows a
caller to ascertain the length of an object prior to calling again
with a supplied buffer of the required size.
If the nextid pointer is supplied then the next
available object ID after objectid is written,
or 0 if no more objects are available.
Return value
On success ENOERR is returned and
the len and nextid
values updated accordingly. If the handler does not recognise the
passed objectid then ENOENT
is returned and *len
is NOT updated. If the
passed *len is not large enough for the object
then EAGAIN is returned
and *len is update with the required length.
| |  | |
| cyg_mbop_write_file_record |  | cyg_mbop_canopen |
| 2025-10-02 | eCosPro Non-Commercial Public License |