Selectingthe Registers - Siemens SIMATIC S5 IP 281 Equipment Manual

Software Settings
3.1.2 Selecting the Registers
Principle of
The registers of the 1P 281 are divided into sets of registers for read and
selection write accesses. Before a register can be accessed, the corresponding
register set must be set with the select register (@ section 3.2).
The desired register can then be read or written via the register address.
Register address The register address consists of the following components.
- The basic address set (via DIL switch S1 for the 1P 281) (-t sect. 2.2)
and
– The offset in the respective register set (-t section 3.2)
Register address = basic address + offset
3 – 2
which is not assigned to a register. The access is acknowledged
with ~
R 11/92