MODBUS is an open protocol used around the world and supported by many different manufacturers. Along with MODBUS, MODBUS/TCP was developed for use in modern networks. This protocol now ranks as an open Internet draft standard introduced to IETF, the Internet Engineering Task Force responsible for Internet standardization.
As a result, manufacturers and users everywhere are free to implement this open protocol, and many leading manufacturers have already taken advantage of this opportunity.
Networking SIMATIC S7 to other systems via MODBUS Industrial Ethernet is a very attractive option, especially when SIMATIC S7 automation systems are being used to expand or modernize legacy configurations or controllers and systems from multiple vendors are being networked.
Different MODBUS software products are available
MODBUS/TCP block for CPs
This MODBUS version is applicable to SIMATIC S7 300 and 400 PLCs. A CP343-1 or CP443-1 is required for the MODBUS communication.
MODBUS/TCP block for CPs with redundancy functionalityThis MODBUS version is applicable to SIMATIC S7 400H systems. A CP443-1 is required for every subsystem for the MODBUS communication. A single S7-400 or S7-300 CPU with 2 CPs can also be employed.
MODBUS/TCP block for PN PLCs
This MODBUS version is applicable to SIMATIC S7 PN PLCs and ET200S PN PLCs. In this case, the integrated PN-interface is used for the MODBUS communication.
MODBUS/TCP block for PN PLCs with redundancy functionalityThis MODBUS version is applicable to SIMATIC S7 PN-H PLCs. In this case, the integrated PN-interface is used for the MODBUS communication.
MODBUS/TCP block for reading data from SENTRON PAC devicesThis MODBUS version is applicable to SIMATIC S7 PN PLCs and ET 200S PN PLCs. In this case, the integrated PN-interface is used for the MODBUS communication. It is possible to read out predefined values of a large number of PAC 3200 and PAC 4200 devices
With the increasing popularity of Ethernet communications in both industry and offices, MODBUS/TCP is enjoying an increasingly broad use in all industries. In particular heterogeneous system landscapes are typical areas of application.
Multi-vendor systems can be easily linked to SIMATIC S7 by Industrial Ethernet
Step-by-step expansion or modernization of legacy systems with the latest SIMATIC technology is highly cost-effective
You can rely on dependable, Siemens-quality support
Using the MODBUS function block requires no specific expertise You benefit from the familiar look and feel of SIMATIC engineering of STEP 7 and PCS 7
For some oft the Modbus/TCP products configuration is supported by a wizard
The configuration is carried out with the standard tool SIMATIC STEP 7. For the MODBUS blocks for the PN PLCs, there are the additional options of a Wizard which provides the possibility of a very fast and comfortable configuration
The function blocks have to be licensed for each CPU
The license is bound to the CPU, transferring the license to a different CPU is not possible.
For testing there is no license required
SIMATIC Modbus/TCP CP for CP 343-1/443-1
Single license for standard systems Software and License Key on CD-ROM
Single license for redundant systemsSoftware and License Key on CD-ROM
SIMATIC Modbus/TCP PN for PROFINET CPUs
Single license for Standard PN systems Software and License Key on CD-ROM
Single license for redundant PN Systems Software and License Key on CD-ROM
SIMATIC Modbus/TCP PN for SENTRON PAC 3200/4200
Single license for connecting 20 SENTRON PAC devicesSoftware and License Key on CD-ROM
Single license for connecting 100 SENTRON PAC devices Software and License Key on CD-ROM
Single license for connecting 512 SENTRON PAC devices Software and License Key on CD-ROM