Specifications

1070 072 131-102 (96.08) GB
BUEP03E Protocol 8-7
8.6 Receive Buffer
8.6.1 UART Receive Buffer
The data received via the serial interface is first filed in the UART Receive
buffer. This Receive buffer is designed as a ring buffer and contains a
total of 384 characters. This buffer is managed by the R500 operating sy-
stem. The characters are read into this buffer via the interface, indepen-
dent of the BÜP03E protocol. The characters are read out character by
character from the BÜP03E log and filed in the BÜP03E Receive buffer.
The oldest character is always read out first. The character, which indi-
cates the internal RD pointer, is read out and the internal RD pointer is
moved by one character. The UART Receive buffer can be reset (flushed)
if the user issues the Reset Receive Buffer command. Information such
as
- Buffer empty
- Character there
- Receive fault
is also available for processing. The receive fault is indicated as a centra-
lised fault (buffer overflow, parity fault...). The BÜP03E protocol responds
to this fault by issuing a Reset command to the UART Receive buffer and
returning a fault message to the user.
Character 1 *RD pointer
Character 2
*WR pointer
Character 383
Character 384
UART Receive buffer
V24 Data
/
Data to be transmitted 20 mA
to R500
HW interface to the peripherals
Fig. 8-3 UART Receive buffer