这个问题其实挺有意思的，要分析明白还真不太容易呢！
首先，看一下我查到的性能参数：

Address area
I/O address area
- Inputs 2 KByte
- Outputs 2 KByte
• of which distributed
- Inputs 2 KByte
- Outputs 2 KByte
Process image
- Inputs 128 Byte
- Outputs 128 Byte
Digital channels
- Inputs 16,384
- Outputs 16,384
- Inputs, of which central 1,024
- Outputs, of which central 1,024
Analog channels
- Inputs 1,024
- Outputs 1,024
- Inputs, of which central 256
- Outputs, of which central 256