Advanced Features; Network Loss Trip; Sync And Freeze Mode - Leroy-Somer digitax st User Manual

12

Advanced features

12.1

Network loss trip

Table 12.1
Pr MM.07
The network loss trip provides a method on the drive to ensure that communication with
the master is still present. The SM-PROFIBUS DP-V1 resets an internal timer when a
valid message is received from the PROFIBUS-DP network, if a message is not
received within the specified period the network loss trip is triggered. If the trip is
generated by SM-PROFIBUS DP-V1, the trip display on the drive will be 'SLx.Er', where
'x' is the slot number where the trip originated. The SM-PROFIBUS DP-V1 error code
parameter (Pr MM.50) will show 65 when a network loss trip has occurred.
The network loss trip is not enabled internally until cyclic data has been detected. This
NOTE
prevents spurious network loss trips while the PROFIBUS-DP master controller is
initialising the PROFIBUS-DP network.
Figure 12-1 Network Loss Trip
Messages Per
Second
If the network loss trip time is reduced too far, spurious network loss trips may occur due
to a time-out occurring before the next message has chance to arrive. The network loss
trip time should be set such that a minimum of four messages will be received in the
specified time period under normal operating conditions.
The network loss trip can be disabled by setting Pr MM.07 to 0. In this case, the drive will
continue to operate using the last received values. It is the user's responsibility to ensure
that adequate safety precautions are taken to prevent damage or injury by disabling the
drive in the event of a loss of communications.
WARNING
12.2

SYNC and FREEZE Mode

The SM-PROFIBUS DP-V1 supports the SYNC and FREEZE modes available with
most PROFIBUS-DP master controllers.
Cyclic data is put into groups by the PLC allowing multiple cyclic channels to be
suspended and updated using the SYNC and FREEZE commands. Data to the drive is
controlled by the SYNC command and data from the drive controlled by the FREEZE
command. The SYNC command is used in conjunction with the UNSYNC command
and the FREEZE command is used in conjunction with the UNFREEZE command.
SM-PROFIBUS-DP User Guide
Issue : a
Network loss trip time-out
Default
Range
Access
Healthy Drive
Communications
www.leroy-somer.com
200 (ms)
0 to 3000 (ms)
RW
Trip Time Set In Pr MM.07
Time
Trip Occurs Here
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