FIFO Read Binary
Simulink® Real-Time™ Library for RS-232
The FIFO Read Binary block reads multiple binary headers from a FIFO.
Note: The Diamond Systems PC/104 boards and blocks will be removed in a future release. Do not use them in new models. Instead, use boards and blocks available from www.speedgoat.com.
This block identifies and separates data by finding unique byte sequences (headers) that mark the data. Each header indicates the start of a fixed length binary message. If the same header has arrived in the FIFO more than once since the block was last executed, the block will discard the older data and only return the latest instance of the header. In this way, the block catches up with data that arrives faster than the block executes.
contains the following examples that illustrate how to use the FIFO
Read HDRS block:
Enter the headers that you want the block to look for in a block
of data from the FIFO. Enter each header as an element in a cell array
either as a quoted character vector or a concatenation with
non-printable byte patterns.
Enter the message length of each byte of data as bytes of data. Include the header in the length.
From the list, select the behavior of the block if the FIFO does not have new data. Select Zero output if no new data if you want the block to have no output if the FIFO has no new data. Select Hold last output if no new data if you want the block to keep the output from the last FIFO message.
This check box enables or disables a FIFO read. Select this check box to turn on a new input that takes Boolean signals that enable or disable the read.
Enter the largest desired read size in bytes. This parameter specifies the width of the output vector and the maximum number of elements to return. See Output vector type for more information about data formats.
From the list, select
count+32 bit int,
count+16 bit int,
8 bit int null terminated,
8 bit uint null terminated. This parameter specifies
the output vector type. The 8-bit data types produce a null terminated
character vector in the output vector. For 16- and 32-bit data types,
the first element contains the number of elements to expect in the
rest of the output vector.
Base sample time or a multiple of the base sample time.