Address Assignment; Addressing; Basic Rules For Addressing; Addressing Example - Festo CPX-E Series Description

2 Function
2.2

Address assignment

The system CPX-E is composed of a different number of inputs and outputs, depending on the number and type of
modules CPX-E used and the parameterisation of the bus module. The inputs and outputs are assigned
automatically within the system CPX-E.
The address assignment (number of allocated inputs and outputs) on the system CPX-E must be determined prior to
commissioning.
– A maximum of 10 I/O modules + bus module is permitted in one system CPX-E.
– The address space of a system CPX-E is limited. The bus module provides the system CPX-E with
a maximum address space of 64 bytes for inputs and 64 bytes for outputs.
– Activated diagnostic functions like status bits or the I/O diagnostic interface reduce the number of
inputs and/or outputs in the available address space.
2.3

Addressing

2.3.1

Basic rules for addressing

– The address assignment of the inputs does not depend on the address assignment of the outputs.
– The counting mode is module-oriented from left to right.
– The bus module counts as a module with 0 inputs and 0 outputs when the status bits and the I/O diagnostic
interface are deactivated.
– Activated status bits occupy 8 inputs.
– An activated I/O diagnostic interface occupies 16 inputs and 16 outputs.
2.3.2

Addressing example

1 Bus module CPX-E-PB
– Status bits activated
– I/O diagnostic interface deactivated
2 Digital input module CPX-E-16DI
3 Digital output module CPX-E-8DO
4 Digital output module CPX-E-8DO
5 Analogue input module CPX-E-4AI-U-I
6 Analogue output module CPX-E-4AO-U-I
Fig. 2.3
The address assignment for the system CPX-E presented is shown in Tab. 2.5.
Module no. Module
0 Bus module CPX-E-PB (with status bits)
1 Digital input module CPX-E-16DI
2 Digital output module CPX-E-8DO
3 Digital output module CPX-E-8DO
4 Analogue input module CPX-E-4AI-U-I
5 Analogue output module CPX-E-4AO-U-I
Tab. 2.5
Festo – CPX-E-PB-EN – 2017-07 – English
Module no.: 0 1
1 2
Input address
E0 ... E7
I8 ... I23
–
–
I24 ... I87
–
2 3 4 5
3 4 5 6
Output address
–
–
A0 ... 7
A8 ... 15
–
O16 ... O79
9