Beckhoff EL6731 Documentation page 52

Parameterization and commissioning
FDL receive
Cmd=255 has to be sent once (see FDL send) to ensure that FDL telegrams can be received. Depending on
the length, ADS-Read is then used to fetch FDL indications received by another master or locally generated
FDL confirmations. An FDL confirmation is returned for each FDL request that is sent.
ADS-Read parameters Meaning
Net-ID
Port
IndexGroup
IndexOffset
Length
Data
52
Net-ID of the master (see the device's ADS [} 92] tab)
200
0xF400
0
Length of the read buffer
Byte Offset Meaning
0 Cmd: 2=indication follows, 4=confirmation follows
1 Indication:
Confirmation
:
2 DA byte (bit 7 indicates whether a DSAP exists)
3 SA byte (bit 7 indicates whether an SSAP exists)
4 Indication:
Confirmation
:
5 n: Length of the following bytes of the indication or confirmation
6 if DA.7=1: DSAP otherwise if SA.7=1: SSAP otherwise first data byte
7 if DA.7=1 and SA.7=1: SSAP otherwise if DA.7=1 or SA.7=1 first data
byte otherwise second data byte
8 if DA.7=1 and SA.7=1: first data byte otherwise if DA.7=1 or SA.7=1
second data byte otherwise third data byte
9-n Further indication or confirmation data; if n is even, an Align byte is
used for filling; (n+1) is always even
n+1 perhaps next Cmd: 2=indication follows, 4=confirmation follows
Version: 2.8
1=response sent (only for SRD indications)
0
0x03=SDA low, 0x05=SDA high, 0x04=SDN low,
0x06=SDN high, 0x0C=SRD low, 0x0D=SRD high
0x00=OK, 0x02=RR, 0x03=RS, 0x08=DL, 0x0A=DH,
0x80=NR, 0x9F,0xAF,0xBF=NA
EL6731