Westermo FD-40 - Manual (Page 19)

19 6630-2242
RBS Reset Buffers and Status signals (bit 5).
At the low to high transition of this command, the receive and
transmit buffers and the status signals RBO, TBO and DEX are cleared.
The command is acknowledged by change state of BLock Ready (BLR).
After state of BLR has been changed, RBS will be set to low (0) again.
Output word 1 (bit 4...0) are not used
These bits will always be set to 0.
Output word 2 to 4 is the output data, with following content:
Word 2 High: Out data byte 1 Low: Out data byte 2
Word 3 High: Out data byte 3 Low: Out data byte 4
Word 4 High: Out data byte 5 Low: Out data byte 6
7.1.2.2 Input data word
Data is transmitted from the FD-40 to the PROFIBUS DP master. The first word is the
added status word and the remaining 3 words are ordinary input data from the receive
buffer.
Word 15 High byte 8 7 Low byte 0
1 VAL TXB TBO RBO DPN IL2 IL1 IL0 BLR WAK ERR DEX – – – –
2 In data byte 1 In data byte 2
3 In data byte 3 In data byte 4
4 In data byte 5 In data byte 6
Input word 1 (bit 15...4) are the serial transfer status bits, with following content:
VAL FD-40 VALid (bit15).
Set to high (1) when the FD-40 is in normal operation.
Set to low (0) when the receive buffer is full or if data received from serial
interface has wrong polarity.
TXB TX Busy (bit 14).
Set to high (1) as long as data is transmitted by the serial interface,
directly or from the transmit buffer.
TBO Transmit Buffer Overflow (bit 13).
Set to high (1) as long as transmit buffer has less than 6 bytes free.
RBO Receive Buffer Overflow (bit 12).
Set to high (1) when the receive buffer has less than 15 bytes free.
Reset to low (0) when the receive buffer has more than 100 bytes free.