Westermo FD-40 - Manual (Page 22)

22 6630-2242
10. Check that transmit buffer has at least 6 byte free by status TBO.
In word 1 bit 13 should be low (0).
11. If more Profibus DP data to transmit buffer, recur to point 5 again.
12. Send buffered data once to serial port by command SFB.
Out word 1, change state of toggle bit 13.
13. Wait for acknowledge, by status WAK.
In word 1, toggle bit 6 shall change state.
Write to Profibus DP in data from Receive buffered data
(received from serial interface):
1. Wait for received frame by checking status DEX.
In word 1, bit 4 should be high (1).
2. Read next to buffer received block by command RNB.
Out word 1 bit 7, change state from low to high.
3. Wait for acknowledge by status BLR.
In word 1, toggle bit 7 shall change state.
4. Read In data Length by status IL2, IL1 and IL0.
In word 1 bit 10-8.
5. If in data length > 0: Read Profibus DP in data word 2–4.
In word 2–4 high and low byte, totally In data Length bytes.
6. Clear received block and reset In Data Length by command RNB.
Out word 1 bit 7, change state from high to low.
7. Read next to buffer received block by command RNB.
Out word 1 bit 7, change state from low to high.
8. Check if more in data blocks by status DEX.
In word 1, bit 4 should be high (1).
9. IF DEX is high (1), recur to point 3 again.