Areas protected from read/write Access by MODBUS Client

As described in the PLC configuration, one write-protected and one read-protected area can be defined for each segment line 0 and line 1. If you try to write to a write-protected area or to read from a read-protected area, an exception response is generated.

Segment exceedance for line 0 and line 1:

A write- or read-protected area that lies in both segments, line 0 and line 1, cannot be accessed with a write/read operation. In case of a segment exceedance, an exception response is generated.

Example

Read 10 words beginning at address := 7FFEhex

This includes the addresses: 7FFEhex…8007hex with the operands %MW0.32766…%MW1.7. Because line 0 is exceeded in this case, an exception response is generated.

Due to this, two requests have to be generated here:

1. Read 2 words beginning at address := 7FFEhex.

2. Read 8 words beginning at address := 8000hex.