5. CONFIGURATION
Output parameters Type Description
DONE BOOL
This variable is true when the block is com-
pletely executed. It is false otherwise.
EXEC BOOL
This variable is true while the block is be-
ing executed. It is false otherwise.
ERROR BOOL
This variable is true when the block con-
cludes the execution with an error. It is
false otherwise. It is connected to the vari-
able DONE, as its status is showed after the
block conclusion.
STATUS SERIAL_STATUS
In case the ERROR variable is true, the
STATUS structure will show the error
found during the block execution. The
possible states, already described in the
SERIAL_STATUS data type, are:
- NO_ERROR
- ILLEGAL_SERIAL_PORT
- PORT_BUSY
- HW_ERROR_UART
- HW_ERROR_REMOTE
- ILLEGAL_RX_BUFF_LENGTH
- RX_TIMEOUT_ERROR
- FB_SERIAL_RX_EXTENDED_NOT
_ALLOWED
- NOT_CONFIGURED
RX_RECEIVED UINT
Returns the received characters num-
ber. This number can be within
zero and the configured value in
RX_BUFFER_LENGTH. In case it is
smaller, an error will be indicated by the
function block.
RX_REMAINING UINT
Returns the number of characters which
are still in the RX queue after the function
block execution.
RX_SILENCE UINT
Returns the silence time in the RX queue,
measured since the last received charac-
ter is finished. The time unit is 10 µs.
This output parameter type is important
to detect the silence time in protocols as
MODBUS RTU. It might not be the si-
lence time after the last received character
by this function block, as it is only true if
RX_REMAINING = 0.
Table 184: SERIAL_RX_EXTENDED Output Parameters
Utilization example in ST language, after the library is inserted in the project and the serial port configured:
PROGRAM UserPrg
VAR
Receive_Ex: SERIAL_RX_EXTENDED;
Port: SERIAL_PORT := COM1;
Buffer_Pointer: ARRAY [0..1023] OF SERIAL_RX_CHAR_EXTENDED;
Status: SERIAL_STATUS;
246
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