8
Manual – DFD11B DeviceNet Fieldbus Interface
3
Features
Introduction
3.3.2
Data exchange via Polled I/O and bit-strobe I/O
SEW drives offer digital access to all drive parameters and functions via the DeviceNet
interface. The inverter is controlled via fast, cyclic process data. Via this process data
channel, you can enter setpoints such as the setpoint speed, ramp generator time for
acceleration / deceleration, etc. as well as trigger various drive functions such as enable,
control inhibit, normal stop, rapid stop, etc. At the same time you can also use this chan-
nel to read back actual values from the inverter, such as actual speed, current, unit sta-
tus, error number or reference signals.
3.3.3
Parameter access via explicit messages
The parameters of the inverter are set exclusively using
explicit messages
. This param-
eter data exchange enables you to implement applications in which all the important
drive parameters are stored in the master programmable controller, so that there is no
need to make manual parameter settings on the drive inverter itself.
3.3.4
Monitoring functions
Using a fieldbus system requires additional monitoring functions for the drive technolo-
gy, for example, time monitoring of the fieldbus (fieldbus timeout) or rapid stop concepts.
You can, for example, adjust the monitoring functions of MOVIDRIVE
®
/ MOVITRAC/
®
specifically to your application. You can determine, for instance, which of the drive in-
verter’s error responses should be triggered in the event of a bus error. For many appli-
cations, a rapid stop function is be useful. However you can also freeze the last setpoints
so that the drive continues to operate with the most recently valid setpoints (e.g., con-
veyor belt). As the range of functions for the control terminals is also guaranteed in field-
bus mode, you can continue to implement rapid stop concepts using the terminals of the
drive inverter, irrespective of the fieldbus used.
®
3.3.5
Diagnostics
The MOVIDRIVE
®
drive inverter and the MOVITRAC
®
B frequency inverter offer you nu-
merous diagnostics options for startup and service. You can, for instance, use the field-
bus monitor integrated in MOVITOOLS
®
MotionStudio to control setpoint values sent
from the higher-level controller as well as the actual values.
3.3.6
Fieldbus monitor
Furthermore, you are supplied with a variety of additional information about the status
of the fieldbus interface. The fieldbus monitor function in conjunction with the
MOVITOOLS
®
MotionStudio PC software offers you an easy-to-use diagnostic tool for
setting all drive parameters (including the fieldbus parameters) and for displaying the
fieldbus and device status information in detail.
