KUNBUS-COM EtherCAT
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The status response has almost the same structure and meaning as
read access with 1 byte. In the event of an error, a 16-bit wide
register address is at position 4 and 5 for this transmission type, at
which the first error occurred. The status is transmitted in the first
transmission block that follows the data block with variable length.
In the event of an error during bulk access (status "2"), the data
transmitted by the module from the data block with variable length is
invalid and must be discarded by the Master.
Transmission block with fixed length
Status code
(1 byte)
Error code
(2 bytes)
Address area
(2 bytes)
Description
0x00
0xXXXX
0xXXXX
NO_PREVIOUS_OPERATION
0x01
0x0000
0xXXXX
READ_SUCCESS
0x02
ERROR_CODE
1
0x0000-0xFFFF
READ_FAILURE
1
See Table “ Error code“
** Address where an error occurs
Transmission block with variable length (1-16/128 words)
Data area
0x0000-0xFFFF"
Simultaneous reading and
writing of more than 2 bytes
with one access (bulk read/
write)
In this access type, the number of source registers to be read or
target registers to be written are transmitted with the first
transmission block that has a fixed length of 5 bytes. After this block
with metadata, the transmission of the read data follows in a
separate transmission block with variable length. Unlike with Bulk-
Read or Bulk-Write, no random start address can be defined for this
access type. The start address for the block to be read is preset with
0x2001 (SSC input register) and with 0x1001 (SSC output register)
for the block to be written. Byte order:
All 16-bit wide register contents to be read or written are prepared by
the module in such a way that the higher-value byte is transmitted as
the first byte and the lower-value byte is transmitted as the second
byte ("Big-Endian" or "Motorola format"). The register contents are
sent in ascending address order, i.e. the start address first.
Transmission block with fixed length
Command code
(1 byte)
Not
used
(2 bytes)
Data length
(2 bytes)
Description
0x40
0xXXXX
1-128
READ_WRITE_BULK
0x00
0xXXXX
0xXXXX
NO_OPERATION*
Components
