Mitsubishi FX0N-32NT-DP, User Manual, Page: 32 / 58

FX0N-32NT-DP Profibus-DP Interface Unit Buffer Memories (BFMs) Allocation 4
4-4
4.3 Data Exchange Status Bit (BFM #20) <Read Only>
BFM #20 contains a status bit for data exchange. If this value is “1", the module is in data
exchange mode and the received data is valid. If this value is “0", the module is not in data
exchange mode.
4.4 Swap Byte Order (BFM #21) <Read/Write>
Some DP-masters handle lower bytes and higher bytes of a word in reverse order compared to
the 32NT-DP module. To enable the module to communicate with these masters, bit 0 of BFM
#21 can be set. If bit 0 is “1”, the low order byte and the high order byte of each user data word
and of the user specific diagnosis will be swapped. Bit 0 of BFM #21 can also be set or reset
by the second user defined parameter byte received from a master. The default value after
power up is “0”.
4.5 Length of Sent Data (BFM #22), Length of Received Data (BFM #23)
<Read Only>
The values held in these BFMs are copied from the send data length and receive data length
settings in the DP-master.