Protection Levels Of A Cpu - Siemens SIMATIC S7-400 Configuration And Use Manual

CPUs of the S7-400
Table 2-1
CPU function
Displays of the block list
Tag monitoring
S7 communication
Read and set time
Status block
Download program to
programming device
Download program to CPU
Delete blocks
Download user program to
memory card
Control tags
Bootstrap via programming
device
If you do not know the password, you can remove the configured security level by
bootstraping the CPU using the operating mode switch. No flash card should be
inserted in the CPU.
Block Protection
You can protect individual blocks. The blocks can then no longer be opened. The
know-how contained in a block remains hidden to anyone not in possession of the
program sources.
Uniform Instruction Set
The STEP 7 programming package is used to program the S7-400. The STEP 7
instruction set is the same for every CPU. This compatibility means that user
programs can run on any CPU. The CPUs only differ in the execution time of the
instructions and the volume (see table 2-2).
The fault-tolerant CPUs of the S7-400H are also programmed with the same
instructions as the S7-400 CPUs. The functional differences between the S7-400
and S7-400H only involve the number of integrated functions and blocks.
2-4

Protection levels of a CPU

Protection level
Access allowed
Access allowed
Access allowed
Access allowed
Access allowed
Access allowed
Access allowed
Access allowed
Access allowed
Access allowed
Access allowed
Protection level
1 2
Access allowed
Access allowed
Access allowed
Access allowed
Access allowed
Access allowed
Password
required
Password
required
Password
required
Password
required
Password
required
Automation System S7-400 Configuration and Use
Protection level
3
Access allowed
Access allowed
Access allowed
Access allowed
Password
required
Password
required
Password
required
Password
required
Password
required
Password
required
Password
required
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