Does the size of the I/O address area have an influence on the size
of the configuration byte?
If you configure a DP/DP coupler with an I/O address area of up to
16 bytes, one configuration byte is required. However, if you
increase the input or output address area to more than 16 bytes
(see Fig. 1 - Using a universal module with an 18 byte I-address
area), this entails two configuration bytes. If you increase the
address area yet further, three configuration bytes are required
from the 33rd byte.
Under normal circumstances, you, as the user, have no influence
over the use of the configuration bytes that are described here.
The configuration bytes do not restrict the specified I/O address
area of the DP/DP coupler either. They only form an internal setup
limit that needs to be watched during configuration.
Fig. 1: Configuring a universal module with 18-byte input address
You can configure up to 16 modules in a DP/DP coupler and the sum
of the configuration data must not exceed 16 bytes. Please pay
watch out for this when using universal modules and address areas
greater than 16 bytes.