Siemens SIMATIC S7-1200

Communication
11.2 PROFINET
S7-1200 Programmable controller
918 System Manual, V4.2, 09/2016, A5E02486680-AK
11.2.11
PLC-to-PLC communication
A CPU can communicate with another CPU on a
network by using the TSEND_C and TRCV_C i
n-
structions.
Consider the following when setting up communications between two CPUs:
● Configuration/Setup: Hardware configuration is required.
● Supported functions: Reading/Writing data to a peer CPU
● No Ethernet switch is required for one-to-one communications; an Ethernet switch is
required for more than two devices in a network.
Table 11- 51 Required steps in configuring communications between two CPUs
Step
Task
1 Establishing the hardware communications connection
A PROFINET interface establishes the physical connection between two CPUs. Since Auto-Cross-Over
functionality is built into the CPU, you can use either a standard or crossover Ethernet cable for the inter-
face. An Ethernet switch is not required to connect the two CPUs.
Refer to "Communication with a programming device: Establishing the hardware communications connec-
tion" (Page 914) for more information.
2 Configuring the devices
You must configure two CPUs in your project.
Refer to "Communication with a programming device: Configuring the devices" (Page 914) for more in-
formation.
3 Configuring the logical network connections between two CPUs
Refer to "PLC-to-PLC communication: Configuring logical network connections between two devices"
(Page 919) for more information.
4 Configuring an IP address in your project
Use the same configuration process; however, you must configure IP addresses for two CPUs (for exam-
ple, PLC_1 and PLC_2).
Refer to "Device configuration: Configuring an IP address for a CPU in your project" (Page 814) for more
information.
5 Configuring transmit (send) and receive parameters
You must configure TSEND_C and TRCV_C instructions in both CPUs to enable communications between
them.
Refer to "Configuring communications between two CPUs: Configuring transmit (send) and receive pa-
rameters" (Page 919) for more information.
6 Testing the PROFINET network
You must download the configuration for each CPU.
Refer to "Device configuration: Testing the PROFINET network" (Page 819) for more information.