The CP 343-5 provides the user with various communication services of the PROFIBUS bus system:

• PG/OP communication
• S7 communication (PG, OP, S7 controllers)
• Open communication (SEND/RECEIVE)
• PROFIBUS FMS (to IEC 61158/61784)

PG/OP communication

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

• S7 routing
  With the aid of routing it is possible to use programming device communication across networks.

S7 communication

S7 communication is used for the coupling

• between SIMATIC S7 automation systems (CP 343-5 server only)
• to HMI devices (OPs).
• to SIMATIC 505
• to PCs, e.g. with CP 5512, CP 5611 A2, CP 5621 and SOFTNET-PB S7 or CP 5613 A2, CP 5613 FO, CP 5614 A2, CP 5623, CP 5624 and HARDNET-PB S7.

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 343-5.

Open communication (SEND/RECEIVE)

Based on Layer 2 (FDL) of PROFIBUS (IEC 61158/61784), the CP 343-5 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 A2, CP 5613 FO, CP 5614 A2, CP 5623, CP 5624
• Non-Siemens systems 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.

PROFIBUS FMS

PROFIBUS FMS, according to PROFIBUS IEC 61158/61784, permits the transmission of messages via various FMS services:

• READ, WRITE;
  for read or write access to variables of the communication partner from the user program (by means of a variable index or variable name),
  for the transfer of its own variable values to the communication partner. Partial access to variable values is supported. The communication is processed over acyclic connections (master/master, master/slave), over acyclic connections with a slave initiative and cyclic connections.
• INFORMATION REPORT;
  (Report) permits unconfirmed transmission of variables by an FMS server. This job type is used particularly for transmission on broadcast FMS connections.
• IDENTIFY;
  for requesting the identification features of the communication partner
• STATUS;
  for requesting the partner status

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

Configuration

STEP 7 V5.1 SP2 or higher is required for configuring the full functional scope of the CP 343-5. 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 using the open communication (SEND/RECEIVE) and FMS can be found in the SIMATIC NET library following installation of STEP 7.