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User manual SCAIME:
NU-Soft-eNod4F-E-0716_235704-C.doc
-
For 16-bits size data, the data is read/written through the 16 last bits. Ignore the 16 upper bits.
Note
: the transaction request register
must
be set to 0x0000 before every new transaction.
7.4
Acyclic exchanges
For DPV1 class 1 and class 2 masters, another mechanism is available to write/read data into/from
eNod4
device.
Acyclic exchanges are supported authorizing a class 1 master to send acyclic requests so as to read or write data into
memory area defined by a couple of slot/index.
A class 2 master can also send the same requests after initiating a connexion (up to 2) with
eNod4
. The
communication happens without disturbing the cyclic data exchange established between the device and the class 1
master.
Note:
be careful when using acyclic read/write requests. The 4-bytes size data are transmitted as 2x16 bits
blocks that need to be inverted so as to keep their consistency. For example 500 000
d
(0007A120
H
) is
read/written through acyclic requests as A1200007
H
.
7.5
eNod4 Profibus DP features
7.5.1
Sync
The
Sync
command can be transmitted from a master to one or more slaves. When receiving this command,
eNod4
device is set into
Synchro
mode. Thus, the cyclic outputs of all the addressed slaves are maintained in their current
state. The cyclic outputs state is not updated until a new
Sync
command is received. The
Synchro mode
stops upon
reception of a
Unsync
command.
7.5.2
Freeze
The reception of a
Freeze
command causes
eNod4
cyclic inputs to be frozen. Their state is not updated until a new
Freeze
command is received. The
Frezze mode
stops upon reception of an
Unfreeze
command.
7.5.3
Fail-safe
eNod4
supports the Profibus DP
Fail-safe
mode. When the Profibus DP master asks
eNod4
to switch to
Fail-Safe
mode,
eNod4
functioning changes according to following rules:
eNod4
Profibus DP cyclic inputs goes on being refreshed
eNod4
Profibus DP cyclic outputs are no more received
eNod4
remains as a “read
-
only device” until the master goes back to a normal working mode.
7.5.4
Profibus DP standard and extended diagnoses
eNod4
diagnosis frame is composed of a standard and a specific (called extended) parts that allow to inform the
Profibus DP master about the device functioning on the communication bus and about device internal errors. The
Profibus diagnosis frame has the following structure:
bytes 1-4
bytes 5-6
byte 7
bytes 8-9
standard diagnosis
length of extended
diagnosis
extended diagnosis
content
status
1
status
2
status
3
Address
Ident Hi
Ident Low
03
XX XX (see table
below)
status 1 & status 2 bytes
: both bytes describe
eNod4
current state from the Profibus point of
view. Bit b
3
of status 1 byte is set to 1 if the extended diagnosis contains one or several errors.
status 3 byte
: always 00
H
Address
: Profibus address if the DP master that parameterized
eNod4
device
Ident. High/Ident. Low bytes
: contain
eNod4
ident number (0D2D
H
)
extended diagnosis content
: