Festo CPX-CTEL4-M12-5POL Manual page 99

4. Diagnostics and error handling
Festo P.BE-CPX-CTEL-EN en 1205NH
Example:
Manual configuration with an I/O length of 8 bytes. Con-
nected is a device with an I/O length of 4 bytes. The
4 bytes of the device are assigned to the first 4 bytes in
the address space of the I-port. The remaining 4 bytes
remain unused.
I-port Fixed I/O length
8 bytes
I-port Byte 0
Byte 1
Byte 2
Byte 3
Byte 4
Byte 5
Byte 6
Byte 7
Fig. 4/3: Device address space less than reserved ad-
dress space
– The recognised device has established a larger I/O
length than in the manual configuration
The system can continue to be operated. But the I/O
bytes that "project" beyond the reserved address space
are ignored.
Example:
Manual configuration with an I/O length of 4 bytes. Con-
nected is a device with an I/O length of 8 bytes. The first
4 bytes of the device are assigned to the 4 bytes in the
address space of the I-port. The remaining 4 bytes of the
device remain unused.
Device:
4 bytes
Byte 0
Byte 1
Byte 2
Byte 3
X
X
X
X
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