Westermo FD-40 - Manual (Page 18)

18 6630-2242
Output word 1 (bit 15...5) are the serial transfer command bits,
with the following content:
EN ENable FD-40 (bit15).
This bit must always be set high (1) for normal operation.
EN bit set to low (0) disable FD-40.
SDO Send actual Data Once, toggle bit (bit 14).
When this toggle bit change state, the number of output data bytes defined
by DL2-DL0 are taken from Profibus DP out data and transmitted directly
over the serial interface.
SFB Send data from transmit buffer, toggle bit (bit 13).
When this toggle bit change state, the content of the transmit buffer will
be continuously transmitted over the serial interface. During transmission
the Transmission Busy status (TXB) will be set to high (1).
Write acknowledge status (WAK) will be changed at transmission
of the first character.
CNF CoNFiguration mode (bit 12).
This bit must always be set low (0) for normal operation.
CTB Copy to Transmit Buffer, toggle bit (bit 11).
When this toggle bit change status, Out data Length (OL2-0) characters
of PROFIBUS DP out data (out data 1–6) will be transferred to the
transmit buffer. Before change state of CTB, the PROFIBUS DP out data
(out data 1–6) and Data Length (OL2-0) must be set.
OL2 Out data Length bit 2 (bit 10).
Bit 2 of the PROFIBUS DP out data length.
OL1 Out data Length bit 1 (bit 9).
Bit 1 of the PROFIBUS DP out data length.
OL0 Out data Length bit 0 (bit 8).
Bit 0 of the PROFIBUS DP out data length.
E.g. For 6 characters PROFIBUS DP out data OL2, OL1 will be high (1)
and OL0 low (0).
RNB Read Next Block (bit 7).
At the low to high transition of this command, the first data block of the
receive buffer will be fetched and written into Profibus DP in data. The In
data Length (IL2-0) defines the number of fetched characters. The Profibus
DP in data is valid when the command is acknowledged by change state of
BLock Ready (BLR).
At the high to low edge of this command, clear the first data block area of
the receive buffer and reset the In data Length (IL2-0).
RAK Read AcKnowledge, toggle bit (bit 6).
This bit will always be set low (0) for normal operation.
Only used when compatibility with earlier product
versions is needed.