Westermo FD-80 - Manual (Page 22)

22 6630-2281
7.2.2.3 Profibus DP communication
This describes the required Profibus DP communication sequence, from a Profibus DP
master unit to FD-80 (A), to get access and data exchange with remote Fieldbus
Adapters.
Preparing for data exchange:
1. Enable normal operation access with FD-10 by command EN
Out word 1, bit 15.
2. Verify accepted EN command by checking status ST.
In word 1, bit 15.
Data exchange with a remote Fieldbus Adapter:
1. Set the Transfer slave address.
Out word 1, low byte.
2. Set Out data (up to 63 word) to this Transfer slave.
Out word 2 ...64.
3. Reset last received Input data and status by the command RES.
Out word 1, toggle bit 11.
4. Transmit output data over serial transfer line by the command SDO.
Out word 1, toggle bit 14.
5. Verify correct sent and received data by checking status ACK.
In word 1, bit 11 is high (1). Alternatively, incorrect sent and received data,has not
been received within 1,500 ms by checking status TO.
In word 1, bit 10 is high (1).
6. If correct received data (ACK OK)
Read In data (up to 63 word) from this Transfer slave TO.
In word 2 ...64.