Technical data

The distributed I/Os system SINEC L2-DP consists of active and passive
stations on the bus.
Active stations (masters) are:
– the programmable controllers
S5-115U/H, S5-135U, S5-150U, S5-155U/H with the master
modules IM308-B and CP 5430 TF/CP 5431 FMS
– PCs or PGs with the appropriate interface card
– programmable controllers of other manufacturers
Passive stations (slaves) are, for example:
– ET200U-DP
– S5-95U L2-DP
– OP 15/20
– DP slaves of other manufacturers
Data transmission using L2-DP (distributed I/Os) provides a standardized
interface for communication between SIMATIC S5 PLCs and field devices
(DP slaves).
Data transmission using DP is particularly easy to handle.
Programming and handling is reduced to a minimum for the user. When
using the DP service, distributed I/Os can be used as if they were modules
plugged into a central controller. With DP, part of the I/O area of the PLC is
occupied by the connected DP slaves with the CP modeling the I/O bytes
used in the direction of the CPU.
This means that access by the user program to the I/O bytes used for
L2-DP, is acknowledged by the CP in place of the distributed I/Os.
Using the L2-DP protocol, the inputs and outputs assigned to the DP slaves
are exchanged cyclically be the CP (see Fig. 11.1).
Distributed I/Os (DP) B89060/02
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