Maximum I/O Configurations - Siemens SIMATIC S7-200 System Manual

1.3

Maximum I/O Configurations

The maximum I/O configuration for each CPU system is subject to the following
limits:
Module count:
CPU 221: no expansion available
CPU 222: maximum of 2 expansion modules
CPU 224 and CPU 226: maximum of 7 expansion modules
No more than 2 of the 7 modules can be intelligent expansion modules
(EM 277 PROFIBUS-DP modules)
Digital Image Register size: The logical space that each CPU allows for digital
I/O is 128 inputs and 128 outputs. Some physical points cannot be realized in
this logical space because this space is allocated in blocks of 8 points. An
8-point block may not be completely realized by a specific module. For
example, the CPU 224 with 10 actual outputs consumes 16 points of logical
output space. A 4-input/4-output module consumes 8 inputs and 8 outputs of
logical space. At the time of printing of this manual, there is no combination of
current release CPU and I/O modules that causes this item to be a limit. It can
be a limit in systems including prior release CPU 22x or future release products.
Analog Image Register size: The logical space allowed for analog I/O is:
CPU 222: 16 inputs and 16 outputs
CPU 224 and CPU 226: 32 inputs and 32 outputs
5V power budget: The maximum 5V current supplied by each CPU is listed in
Table 1-2. Total current of all expansion modules in the system cannot exceed
this budget. See Section 2.5 for further information on power considerations.
Table 1-3 shows the maximum I/O configuration allowed for each S7-200 CPU.
S7-200 Programmable Controller System Manual
A5E00066097-02
Introducing the S7-200 Micro PLC
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