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Manual – DFD11B DeviceNet Fieldbus Interface
6
Return codes for parameter setting via explicit messages
DeviceNet Characteristics
6.3
Return codes for parameter setting via explicit messages
SEW-specific
return codes
The return codes which the inverter sends back in the event of incorrect parameter set-
ting are described in the manual for the fieldbus device profile and do not form part of
this documentation. However, the return codes are sent back in a different format in con-
junction with DeviceNet. The following table shows the data format for a parameter re-
sponse telegram.
• MAC-ID is the DeviceNet address
• The
Service code
of an error telegram is always
94h
hex
• The
General Error Code
of an inverter-specific return code is always
1F
hex
= propri-
etary error
• The additional code is identical to the
additional code
described in the
SEW fieldbus
device profile manual.
The table shows the proprietary error
10
hex
= Illegal parameter index.
Return codes
from DeviceNet
DeviceNet-specific return codes are sent in the error message if the data format is not
maintained during the transfer or if a service is performed which has not been imple-
mented. The coding of these return codes is described in the DeviceNet specification
(
→
section "General Error Codes").
Timeout of
explicit mes-
sages
The timeout is triggered by the DFD11B option. The timeout interval must be set by the
master after the connection has been established. The DeviceNet specification refers to
an 'expected packet rate' rather than a timeout interval in this case. The expected packet
rate is calculated on the basis of the timeout interval using the following formula:
t
Timeout_ExplicitMessages
= 4 x t
Expected_Packet_Rate_ExplicitMessages
It can be set using connection object class 5, instance 1, attribute 9. The range of values
runs from 0 ms to 65535 ms in 5 ms steps.
If a timeout is triggered for the explicit messages, this connection type for the explicit
messages is automatically dropped provided that the polled I/O or bit-strobe connec-
tions are not in the ESTABLISHED state. This is the default setting of DeviceNet. The
connection for explicit messages must be re-established to communicate through these
messages again. The timeout is
not
forwarded to the inverter.
Byte offset
0
1
2
3
Function
MAC-ID
Service code [=94hex]
General error code
Additional code
Example
01
hex
94
hex
1F
hex
10
hex
0
0
I
