Technical data

Table Of Contents
Organization Blocks
System Software for S7-300/400 System and Standard Functions - Volume 1/2
A5E00709327-01
1-33
The variables OB81_RESERVED_i, 3 i 6 indicate the expansion racks on
which the battery backup (error code B#16#31), the back-up voltage (error code
B#16#32) or the 24-V power supply (error code B#16#33) has failed or returned.
The following table shows what bit is assigned to which expansion rack in the
variables OB81_RESERVED_i, 3 i 6.
OB81_RESERVED_6 OB81_RESERVED_5 OB81_RESERVED_4 OB81_RESERVED_3
Bit 0 Reserved 8th expansion rack 16th expansion rack Reserved
Bit 1 1st expansion rack 9th expansion rack 17th expansion rack Reserved
Bit 2 2nd expansion rack 10th expansion rack 18th expansion rack Reserved
Bit 3 3rd expansion rack 11th expansion rack 19th expansion rack Reserved
Bit 4 4th expansion rack 12th expansion rack 20th expansion rack Reserved
Bit 5 5th expansion rack 13th expansion rack 21st expansion rack Reserved
Bit 6 6th expansion rack 14th expansion rack Reserved Reserved
Bit 7 7th expansion rack 15th expansion rack Reserved Reserved
The bits in the variables OB81_RESERVED_i have the following meaning (for the
expansion rack concerned):
When the event occurs, the expansion racks are marked (the corresponding bits
are set) on which at least one battery or back-up voltage or the 24 V power supply
has failed. Expansion racks on which at least one battery or back-up voltage or the
24 V power supply failed earlier are no longer indicated.
When the event is eliminated and the backup is restored on at least one expansion
rack, this is signaled (the corresponding bits are set).
The following table shows the event that started OB81:
OB81_EV_CLASS
OB81_FLT_ID Meaning
B#16#39/B#16#38 B#16#21: At least one back-up battery of the central rack is
exhausted/problem eliminated (BATTF)
Note: This event occurs only if one of the two batteries fails (if
there are redundant back-up batteries). If the second battery
should also happen to fail, the event will not occur again.
B#16#39/B#16#38 B#16#22: Back-up voltage in the central rack failed/problem eliminated
(BAF)
B#16#39/B#16#38 B#16#23: Failure of the 24 V power supply in the central rack/problem
eliminated.
B#16#39/B#16#38 B#16#25: At least one back-up battery in at least one redundant central
rack is exhausted/problem eliminated (BATTF)
B#16#39/B#16#38 B#16#26: Back-up voltage in at least one redundant central rack
failed/problem eliminated (BAF)
B#16#39/B#16#38 B#16#27: Failure of the 24 V supply in at least one redundant central rack
B#16#39/B#16#38 B#16#31: At least one back-up battery of at least one expansion rack is
exhausted/problem eliminated (BATTF).
B#16#39/B#16#38 B#16#32: Back-up voltage in at least one expansion rack failed/problem
eliminated (BAF)
B#16#39/B#16#38 B#16#33: Failure of the 24 V power supply in at least one expansion
rack/problem eliminated.