UM EN FLX ASI SYS PRO INST - Onlinecomponents.com

UM EN FLX ASI SYS PRO INST
1.7 System Components of the AS-Interface System
An AS-i system consists of at least the components described below.
1.7.1 Masters/Gateways
Slave profile
An AS-i master (gateway) is used to integrate an AS-i system into a higher-level fieldbus.
These are "intelligent" units in the AS-i system, which are responsible for serial
communication and self-diagnostics in the system. For the control system or in the higherlevel
network, the AS-i system is represented in the corresponding process data, which can
be accessed in the normal way.
1.7.2 Power Supply Units
AS-Interface networks are supplied by special power supply units. These power supply
units provide as DC voltage of 29.5 V to 31.6 V at the output side. This is necessary in order
to safely operate all the sensors and actuators with the 24 V nominal voltage in the AS-i
system. In addition, with an integrated data decoupling network the power supply unit
ensures that data can superimpose the supply voltage. AS-i power supply units meet the
requirements of "functional extra-low voltages with safe isolation (PELV)". Outputs are
usually supplied separately via a black power cable. These standard power supply units
must also meet the requirements of PELV. This ensures that in the event of a device fault
the AS-i system cannot output any hazardous voltages.
1.7.3 Slaves
Through the concentration of special AS-i functions in the compact protocol chip a wide
range of termination devices can be adapted for use in the AS-i system. These termination
devices are the devices on the bus, i.e., the slaves. I/O devices are AS-i slaves, which
integrate several devices of conventional (parallel) type in AS-i systems.
Each slave is identified by a slave profile. The slave profile is used for clear, functional
identification by the AS-i master. The specifications for this are defined in the AS-Interface
specification and comprise an ID code, two extended ID codes (ID1 code and ID2 code),
and a configuration code for inputs/outputs (IO code). This data indicates the function of the
slave.
The slave profile looks like this: S-7.A.0. It comprises the IO code, ID code, and ID2 code, it
cannot be modified and is permanently programmed by the manufacturer.
onlinecomponents.com
All information in the slave profile (ID, ID1, ID2, and IO code) is required in order to easily
replace slaves within an existing system. The master uses this data to check whether the
actual configuration matches the desired configuration.
1-8 PHOENIX CONTACT 7513_en_01