Control Bit Configuration - ABB Relion 620 Series Protocol Manual

Section 3
Vendor-specific implementation
3.4.6.4
36
Enhanced security object
• Positive confirmation means that control has been activated. The application
behind the control point has started, but has not yet finished. SSR6 state is set into
'In progress'.
• Exception 03 response means that the control is not activated. SSR6 reason code
is updated.
After a positive confirmation, SSR6 state is set to 'Ready' when the application
control eventually is terminated. SSR6 reason code is updated with either a positive or
a negative reason code.
Impact on master's logic
Only one control sequence can be performed at a time by the IED. A new Modbus
control command cannot be accepted by the IED after an enhanced security object
control, until the SSR6 state is set to 'Ready'.
Enhanced security objects are in practice always Double Point objects. For example,
in the case of a control made to a motor-controlled disconnector, the control sequence
lasts 10 seconds. Master can monitor the command progress.
• By polling the SSR6 register and examine the state bits. Control can be in state 'In
progress' for 10 seconds.
• Double Point object .stSeld attribute is set to '1' while the control operation is in
progress. This also lasts for 10 seconds.
• The control should result in some input data eventually changing position. This
input data could be monitored to determine that the control operation is over. This
should also take 10 seconds.

Control bit configuration

Control bits are write-only coil (0x) data. In addition, some of the control bits are
assigned in parallel to holding register (4x) control structures.
Control bits can be accessed in the Modbus Communication Management tool in
PCM600, under the tab: 0x – writable coils.
1MRS757645 B
620 series
Communication Protocol Manual