Westermo FD-40 - Manual (Page 21)

21 6630-2242
7.3.2.3 PROFIBUS DP communication
This describes the required PROFIBUS DP communication sequence from a PROFIBUS DP
master to an FD-40 B, to get access and data exchange with the serial interface of FD-40.
Preparing for all type of data exchange:
1. Enable normal operation by command EN.
Out word 1, bit 15 set high (1).
2. Check that FD-40 is in normal operating condition by checking status VAL.
In word 1, bit 15 should be high (1).
Send PROFIBUS DP out data direct (up to 6 byte) to serial interface:
1. Write PROFIBUS DP out data word 2–4 to be sent from serial interface.
Out word 2–4.
2. Set Out data length OL2, OL1 and OL0.
Out word 1 bit 10–8.
3. Check that serial interface is ready to transmit, by status TXB.
In word 1 bit 14 should be low (0).
4. Send actual data once by command SDO.
Out word 1, change state of toggle bit 14.
5. Wait for acknowledge, by status WAK.
In word 1, toggle bit 6 shall change state.
Send PROFIBUS DP out data to transmit buffer, and finally send all buffered
data to serial interface once:
1. Reset buffers and status signals by command RBS.
Out word 1 bit 5, at edge of low to high state.
2. Wait for acknowledge, by status BLR.
In word 1 toggle bit 7 shall change state.
3. Reset the RBS command.
Out word 1 bit 5 set to low (0).
4. Check that FD-40 is in normal operation by status VAL.
In word 1 bit 15 should be high (1).
5. Write Profibus DP out data word 2–4 to be loaded in transmit buffer.
Out word 2–4.
6. Set Out data length OL2, OL1 and OL0.
Out word 1 bit 10–8.
7. Copy to transmit buffer by command CTB.
Out word 1, change state of toggle bit 11.
8. Wait for write acknowledge by status WAK.
In word 1 toggle bit 6 shall change state.
9. Check that last command was correct by status ERR.
In word 1 bit 5 should be low (0).