Siemens S5-135U/155U System Manual page 289

Jumpers to
All the output signals required for coordination (arbitration) can be
Switch off the
interrupted by removing a jumper plug. This is necessary to operate the COR
Coordination 923C as a PG multiplexer in the EU S5-185U.
Signals
When the unit is delivered, all jumpers are closed.
Fault Register The fault register is an 8-bit register and is readable by the CPU under
address FEFFH. The register is written to by the bus monitor in the event of a
bus error. Each CPU is assigned one bit of the fault register which is set to 1
in the event of an error. The register is cleared each time the Stop signal
becomes inactive.
The fault register can be read by all CPUs, allowing central functions to be
initiated.
Note
The fault register and the page register are at address FEFFH (FFEFFH with
the CPU 948). The page register is addressed by writing to FEFFH, and the
fault register is addressed by reading out FEFFH.
System Manual
C79000-G8576-C199-06
Coordination Section
in operation
All jumpers of EP 61 closed
8
EP 61
9
7 4 3 2 1
Not assigned
Multiprocessor Operation/Coordinators
out of operation
All jumpers of EP 61 open
1
16
0
Fault register FEFFH
Bit = 1: Bus error from CPU 1
Bit = 2: Bus error from CPU 2
Bit = 3: Bus error from CPU 3
Bit = 4: Bus error from CPU 4
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