When building an application of PLC STEP7, the first step is to make the Project of S7 and configure the hardware. This article gives the rules to be practical when choosing parameters. The rules below show the exclusions.
1. CPU Configuration
• Straight away a CPU is put in a Rack, the first parameter required is the address of IP on the network. This interface is linked to the PON. The CODAC controls the plan of IP address on the PON and will supply the information. There is not require to construct a network. It will be needed when PLCs are interrelated in the plant system.
• Double-Click the hardware config on the CPU and select the tab of “General”. In the text field of “Comment”, initiate the PLC PBS number, the cubicle PBS and location.
• Select the tab of “Cycle/Clock Memory”. Check “Clock Memory” and bring in “100” in the field of “Memory Byte”.
• Select the tab of Startup. Check “Cold Restart” for Startup following Power On.
• Double-Click on filed of X5-PN:IO of the CPU. Select the tab of “time-of-Day Synchronization. Check “Enable Time of Day synchro in NTP Mode”. Bring in 2 NTP Servers Address.
• Write down 60 in “Update Interval”.
Immediately a CP is put in the Rack, the first parameter applied for is the network IP Address. This network is the network of Profinet, actually divided from the PON. The address default can be left as it is. There is not require to have a particular IP Address Plan. Build a New Network in Subnet, with default parameters. Click the right button- on the “X1 PN-IO”, field of the CP and choose “insert PROFINET IO System”.
Configuration of Remote IO Rack
While installing a rack of remote IO in the network of Profinet the only parameter to identify is the name. This name is vital because it is used by the network communications of Profinet. In the Rack of the “Comment” text field, the PBS location and number of the cubicle should be stated. The default addresses recommended by STEP 7 will be implemented when inserting the IO boards in the racks. It is essential to follow this rule because according to the type of boards Step 7 selects specific areas of Input/Output.
The boards in the racks of remote IO have to be placed in the following order:
1. Boards of Digital input
2. Boards of Digital output
3. Boards of Analog input:
3.1. Boards of thermocouple input
3.2. 0..10V, 4-20mA, etc.
3.3. Boards of RTD input
4. Boards of Analog output