Siemens SIMATIC NET CP 243-1, Operating Instructions Manual

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Application and properties
1.6 IT communication
CP 243-1
Operating Instructions, 03/2012, C79000-G8976-C244-02
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– Data type is BOOL, BYTE, WORD or DWORD
– The use of the data types CHAR, INT, DINT and REAL depends on the firmware
version of the S7-200 CPU being used.
– Accessible memory areas on the local system are inputs, outputs, variables, bit
memory, system area and status bits.
Note
When an S7-300 or S7-400 is acting as the server for a client running on an S7-200
system, the CP 243-1 expects that this server will always have a passive role. This
means that, the S7-300 or S7-400 system is not allowed to send S7 requests to the
S7-200 system.
Communication with STEP 7 Micro/WIN 32
With communication between a CP 243-1 and STEP 7 Micro/WIN 32, the CP 243-1 is
always the server. STEP 7 Micro/WIN 32 always acts as the client.
S7 bus communication
All access to all data areas of the S7-200 CPU is always possible. Read and write access
does not depend on the CPU mode (RUN, TERM or STOP).
1.6 IT communication
1.6.1 Preliminary overview
Preliminary overview
The CP 243-1 supports not only S7 communication via Industrial Ethernet but also a series
of IT functions at the same time. These include data exchange via FTP, sending e-mails, and
the option of permitting up to four Web browsers to access data and status information
simultaneously on the S7-200 system.
Sending an e-mail or active file access using FTP is initiated by the S7-200 user program.
Only one request can be active for each of these two functions at any one time. The user
program cannot start another request until the CP 243-1 has positively or negatively
acknowledged the currently active request.