4
Commissioning
Festo – P.BE-CPX-FB37-EN – 1406NH – English
27
Detailed information on the electric and pneumatic CPX modules can be found on the
Festo website (
www.festo.com/sp).
4.3
Addressing the inputs and outputs, data access
4.3.1
Basic rules for addressing
–
The bus node counts as a module with 0 inputs and 0 outputs when the status bits and the I/O dia-
gnostic interface are deactivated.
–
Observe the notes regarding address assignment in section 4.2.
–
Modules with less than 8 bits occupy 8 bits or 1 byte of address space, but do not use all this space.
–
The addressing sequence differs between MDP and a fixed I/O size (CPX-FB38 mode).
If necessary, status bits or the I/O diagnostics interface can be activated via DIL switch
(
Tab. 3.3):
–
If the 8 status bits are activated, they will occupy 16 inputs in the address range
(8 used).
–
If the I/O diagnostics interface is activated, it will occupy 16 inputs and outputs in the
address range.
4.3.2
Differences in addressing between the modular device profile and fixed I/O size
Sequence of addressing — Modular Device Profile (CPX-FB37 mode)
The I/O addresses are assigned in ascending order according to the module position.
Sequence of addressing — fixed I/O size (CPX-FB38 mode)
If the bus node is set to a fixed I/O size using DIL switch 2 (
Section 3.2.5), the following rules shall
apply (
Tab. 4.1):
Sequence of addressing
Description
1.
Status bits or I/O diagnostics
interface
Delivers status and diagnostic information; activate through
DIL switches; occupies the first 16 inputs or inputs and
outputs
2.
Analogue modules
Modules with analogue inputs/outputs
3.
Technology modules
e. g. CP interface, front end controller (CPX-FEC), CoDeSys
controller (CPX-CEC)
4.
Digital modules
Modules with digital inputs/outputs
Tab. 4.1
Sequence of addressing in CPX-FB38 mode
A detailed description of the addressing process and various addressing examples for the
CPX-FB38 mode can be found in the description of the bus node CPX-FB38
(
P.BE-CPX-FB38).
