Functions
2.2 Protection Data Interfaces and Protection Data Topology
SIPROTEC, 7SD5, Manual
C53000-G1176-C169-5, Release date 02.2011
80
Principle of function
In the following, the logic is shown in a simplified way:
Figure 2-12
Logic diagram for switching the "Log out device" mode
If a command (from DIGSI or keypad) or a binary input requests the change of the current mode, this request
is checked. If
„Logout“
ON or
„>Logout ON“
is requested, the following is checked:
• Is the local circuit breaker open?
• Is the communication of the remaining devices ensured?
• Is the device not operating in differential protection test mode?
If all requirements are met, the request is accepted and the indication
„Logout“
ON (No. 3484) is generated.
According to the request source, either the indication
„Logout ON/off“
ON (No. 3459) or
„Logout
ON/offBI“
ON (No. 3460) is output. As soon as a requirement is not met, the device is not logged out.
If the device is to be logged on to the line protection system (
„Logout“
off or
„>Logout OFF“
), the following
is checked:
• Is the local circuit breaker open?
• Is the device not operating in differential protection test mode?
If all requirements are met, the request is accepted and the indication
„Logout“
OFF (No. 3484) is generated.
According to the request source, either the indication
„Logout ON/off“
OFF (No. 3459) or
„Logout
ON/offBI“
OFF (No. 3460) is output. As soon as a requirement is not met, the device is not logged on.
Note
The device can deny the logout if one of the conditions mentioned before is not fulfilled. Please consider this
behaviour when requesting the messages via a binary input.