Siemens SIMATIC Distributed I/O System DP/ASi Link Manual page 139

Distributed I/O Distributed I/O devices are I/O units that are not used in the base unit but are
devices set up on a distributed basis; for example:
Distributed I/O devices are connected to the DP master over the PROFIBUS-
DP bus.
DP
DP stands for "distributed I/O".
DP master
The DP master is an
stations according to a defined algorithm and makes data available to the
user. Its behavior conforms to standard EN 50170 Volume 2, PROFIBUS.
DP slave
DP standard
Abbreviation for standard EN 50170 Volume 2, PROFIBUS.
DP standard slave A DP standard slave is a
standard EN 50170 Volume 2, PROFIBUS.
F
FREEZE FREEZE is a control command of the DP master to a group of DP slaves.
Upon receiving the FREEZE control command, the DP slave freezes the cur-
rent state of the inputs and transmits the frozen data periodically to the DP
master.
After every FREEZE control command thereafter, the DP slave freezes the
current state of the inputs again.
The input data are not sent periodically to the DP master by the DP slave
again until the DP master sends an UNFREEZE control command.
I
I/O code The I/O code specifies the assignment of inputs and outputs to the data bits.
The I/O code defines sixteen different input/output combinations.
Distributed I/O System DP/ASi Link
EWA 4NEB 710 6055-02b
ET 200 family
S5-95U with PROFIBUS-DP interface
DP/ASi link
other DP slaves from Siemens or external devices.
active node which communicates with the DP slave
DP standard slave
passive node which behaves in accordance with
Glossary
Glossary-3