Siemens SIMATIC RF1000 Series, Руководство по эксплуатации

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Programming
6.2 Programming via USB/RS232 interface (using DLL functions)
SIMATIC RF1000
Operating Instructions, 02/2020, C79000-G8976-C432-07
35
6.2.1.12 vhl_is_selected
This function checks whether the card selected the last time the "vhl_select" function was
executed is still or once again located in the antenna field. If the card is there, the status
"OK" is returned.
Note that this function always returns the return value "CARD_NOT_SELECTED_ERR"
when a card is displayed to the reader without the "vhl_select" function being executed first.
Function call
int
vhl_is_selected(
int Handle,
int * Status
);
Table 6- 14 Description of the parameters
Parameter Description
vhl_is_selected This function call checks if the card selected during the last execution of the
"vhl_select" function is still in the antenna field or if it has returned to the
antenna field.
Handle The session key returned by the "brp_open_usb_session" or
"brp_open_serial_session" function.
Status
•
OK
•
CARD_NOT_SELECTED_ERR
You will find more information on the reader status in the section "Status
codes (Page 55)".
Return value
• BRP_OK
You will find more information on return values in the section "Return val-
ues (Page 40)".