Table 7: ethercat command details – BECKHOFF EtherCAT Technology Section I User Manual
Page 31

EtherCAT Protocol
Slave Controller
– Technology
I-11
Table 7: EtherCAT Command Details
CMD
High
Addr. In
High
Addr.
Out
Low
Addr.
Address Match
Data
In
Data
Out
WKC
NOP
untouched
none
untouched
APRD
Position
Pos.+1
Offset
ADP=0
-
Read
+0/1
APWR
Position
Pos.+1
Offset
ADP=0
Write
+0/1
APRW
Position
Pos.+1
Offset
ADP=0
Write
Read
+0/1/2/3
FPRD
Address
Offset
ADP=conf.
station addr.
-
Read
+0/1
FPWR
Address
Offset
ADP=conf.
station addr.
Write
+0/1
FPRW
Address
Offset
ADP=conf.
station addr.
Write
Read
+0/1/2/3
BRD
High Add.
In+1
Offset
all
Data
In OR
Read
+0/1
BWR
High Add.
In+1
Offset
all
Write
+0/1
BRW
High Add.
In+1
Offset
all
Write
Data
In OR
Read
+0/1/2/3
LRD
Logical address
FMMU
-
(Read AND
bitmask
1
)
OR
(Data In
AND NOT
bit_mask
+0/1
LWR
Logical address
FMMU
Write
+0/1
LRW
Logical address
FMMU
Write
(Read AND
bit_mask
OR
(Data In
AND NOT
bit_mask
+0/1/2/3
ARMW
Position
Pos.+1
Offset
Read: ADP=0
-
Read
+0/1
Write: ADP/=0
Write
+0/1
FRMW
Address
Offset
Read: ADP=
conf. station
address./alias
-
Read
+0/1
Write: ADP/=
conf. station
address./alias
Write
+0/1
NOTE: Working Counter (WKC) increment depends on address match
1
bit_mask depends on FMMU configuration if bit-wise mapping is used: only masked bits are actually addressed
by the logical read/write command.