The CP 342-5 provides access to different communication services of the PROFIBUS bus system:

• PROFIBUS DP (according to IEC 61158/61784, master or slave)
• PG/OP communication
• S7 communication (client, server)
• Open communication (SEND/RECEIVE)

PROFIBUS DP master

The CP 342-5 operates as a DP-V0 Master according to IEC 61158/EN 61784 Volume 2 and processes the data transfer completely independently. It supports the services of the Master Classes 1 and 2.

The data areas of the distributed I/Os are transferred consistently between CP and CPU. This applies to the use of the CP as DP Master and as DP Slave. As DP Master, it permits connections to:

• SIMATIC S7-300, such as CP 342-5 as DP slave
• DP slaves of the distributed I/O system ET 200 (integrate as DP-V0 slave)
• PCs, e.g. with CP 5512, CP 5621, CP 5614 A3 and SOFTNET-PB DP

The CP 342-5 also offers the SYNC/FREEZE and shared input/output functions, as well as the activation/deactivation of DP slaves.

PROFIBUS DP slave

The CP 342-5 as a DP-V0 slave permits the SIMATIC S7-300 to exchange data with other PROFIBUS DP masters. which allows a hybrid setup between SIMATIC S5/S7, PCs, ET 200 and other field devices to PROFIBUS DP. Function calls are required for the DP communication. These (DP-SEND/DP-RECV) must be integrated in the STEP 7 user program.

PG/OP communication

PG/OP communication allows all S7 stations connected to the network to be remotely programmed.

• S7 routing
  With the aid of S7 routing it is possible to use programming device communication across networks.
  Via the CP 342-5 as many as 16 TD/OPs can be merged into one S7-300 station. This requires only one connection resource in the S7-CPU (multiplex channel). The multiplex channel supports the acyclic HMI services.

S7 communication

S7 communication is used for the coupling:

• between SIMATIC S7 automation systems
• to HMI devices (OPs).
• to PCs, e.g. CP 5711 with SOFTNET-PB S7, CP 5623 etc.

Communication with PG and OP takes place without further configuration. In addition, the central controller can also be programmed and configured on a distributed basis via the CP 342-5.

The client functionality is provided by means of loadable communication blocks.

Open communication (SEND/RECEIVE)

Based on Layer 2 (FDL) of PROFIBUS, the CP 342-5 offers a simple, optimized interface for process or field communication.

This interface offers integrated, high-performance communication between SIMATIC S5, SIMATIC S7, SIMATIC 505 and PC. SEND/RECEIVE provides not only the SDA service (PLC/PLC connections) but also the SDN service (broadcast, multicast).

The communication partners are the automation systems:

• SIMATIC S7
  with CP 342-5, CP 343-5, CP 443-5 Extended and Basic
• SIMATIC S5
  with S5-95U with PROFIBUS interface, S5-115U/H, S5-135U, S5-155U/H with CP 5431 FMS/DP
• SIMATIC 505
  with CP 5434-FMS
• PCs
  with CP 5512, CP 5611 A2, CP 5621, CP 5613 A3, CP 5613 FO, CP 5614 A3, CP 5623, CP 5624
• Systems of other makes that are equipped with an FDL interface.

To use SEND/RECEIVE, function calls are required (PLC-SEND/PLC-RECEIVE), which must be linked into the STEP 7 user program.

Diagnostics

Extensive diagnostic options are available via STEP 7, including:

• Status of the CP
• General diagnostics and statistics functions
• Connection diagnostics
• Bus statistics
• Message buffer

STEP 7 V5.5 SP2 or higher, or STEP 7 Professional V11 or higher, is required for configuring the full functional scope of the CP 342-5. In Version V5 or higher of STEP 7, the configuration data of the CP can also optionally be stored on the CPU and is retained even if there is a power failure. A module can therefore be replaced without having to reload the configuration data from a programming device. The CPU transfers the configuration data to the CP during start-up. Attention should therefore be paid to the memory capacity of the S7-CPU.

Configuration and programming of all SIMATIC S7 controllers connected to the network is possible over the network.

The function blocks for PROFIBUS DP are included in the standard library of STEP 7. The function blocks for using the open communication (SEND/RECEIVE) and S7 communication (S7 client) can be found in the SIMATIC NET library following installation of STEP 7.