Siemens SIMATIC NET CP 243-1, Operating Instructions Manual

Page: 54 / 142

Configuration
3.2 Value ranges of the configuration data
CP 243-1
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Operating Instructions, 03/2012, C79000-G8976-C244-02
The configuration data stored in the memory of the S7-200 CPU can be downloaded to the
S7-200 CPU via the PPI interface. If the CP 243-1 already has an IP address, this
configuration data can also be downloaded to the S7-200 CPU using TCP/IP and the
Ethernet interface of the CP 243-1. The CP 243-1 must already have an IP address before
the configuration data of the IT services can be downloaded to the CP 243-1. If you want an
S7-200 system to communicate via a CP 243-1 with an S7-300, an S7-400 or an OPC-based
system, use STEP 7 with at least version 5.1 and service pack 3 or higher (with NCM S7 for
Industrial Ethernet) for configuration.
Note
After startup, the CP 243-1 may automatically change the configured gateway due to special
network-based services ("ICMPRedirect"). After approximately 30 seconds, however, the CP
243-1 returns to the originally configured gateway. This means that the gateway actually
used by the CP 243-1 may sometimes differ from the one in the configuration.
You can change the gateway currently used by the CP 243-1 either using the diagnostics
window for the CP 243-1 in STEP 7 Micro/WIN 32 or a user program that reads from the
memory area of the S7-200 CPU in which the NPB data block is stored (see chapter
Structure of the network parameter block (NPB) (Page 72)).
3.2 Value ranges of the configuration data
3.2.1 IP addresses
The IP addresses that need to be specified at various points in the configuration must
comply with the general conventions governing the validity of IP addresses.
According to this convention, the following IP addresses have a special significance:
Loopback 127.0.0.0 - 127.255.255.255
Class D addresses 224.0.0.0 - 239.255.255.255
Class E addresses 240.0.0.0 - 247.255.255.255
Broadcast addresses for example 255.255.255.255
The CP 243-1 does not accept these addresses. The only exception is the loopback address
127.0.0.1 that can be used during configuration of the FTP client service. This causes data
to be transferred between the memory of the local S7-200 CPU and the file system of the
local CP 243-1 when the relevant function is called.
3.2.2 Subnet mask
If a subnet mask is specified in the configuration, its structure must comply with the general
conventions governing the validity of subnet masks.