Address Assignment; Addressing; Basic Rules For Addressing; Addressing Example - Festo CPX-E-PN Manual

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 as well as status bits or the I/O diagnostic interface reduce the size
of the available address space.
2.3

Addressing

2.3.1

Basic rules for addressing

– The address assignment of the inputs is independent of the address assignment of the outputs.
– 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.
– The inputs and outputs of different module types are assigned separately from each other.
Addressing is generally carried out by the higher-order controller (in cases where a Siemens higher-order
controller is being used).
2.3.2

Addressing example

1 Bus module CPX-E-PN (with status bits)
– 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
Tab. 2.3 shows the address assignment for the system CPX-E pictured here, in a TIA portal with a Siemens PLC.
Module no. Module
0 Bus module CPX-E-PN (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. 2.3
8
Module no.: 0 1
1 2
Input address
Byte 68
Byte 1 ... 2
–
–
Byte 69 ... 76
–
Festo – CPX-E-PN-EN – 2017-07 – English
2 4 5
3
3 4 5 6
Output address
–
–
Byte 1
Byte 2
–
Byte 64 ... 71