Example Function Block To Shift Buffer And Insert Data

Sometimes it is necessary to byte shift data right by one byte to insert a new byte at the head of a buffer. This could be for strings or data. However the current PLC shift instructions don't enable this function easily as data is often byte swapped in a word.

The attached sample CX-Programmer file includes a Function Block (FB) which allows users to shift a 'buffer' of data by one byte. The FB also inserts a new byte at the head of the buffer.