Manual VIPA System 300V
Chapter 1 Basics
HB130E - CP - RE_343-2AH10 - Rev. 08/41
1-5
Basics AS-i
AS-Interface (AS-i=
A
ktor-
S
ensor-
i
nterface) may be deployed at the field
area as a communication system. It serves for the connection of sensors
and actuators at the lowest control level with the goal to compensate the
parallel wiring.
Data and energy (max. 8A) are transferred by the same line at AS
interface. Here non-shielded 2-wire lines are used.
AS-Interface is a single master system. Data were cyclically (max. 10ms)
exchanged between AS-i master and each configured AS-i slave by means
of a serial protocol.
Here one telegram has 4bit user data. Up to 62 AS-i slaves may be
connected to one AS-i master according to the specification 2.1
Plant control level
Process and production level
Sensor-/actuator level
TCP/IP
Ethernet
Fieldbus systems
e.g. Profibus, CAN-Bus,
Interbus, DeviceNET
AS-i
Within an AS-i net each AS-i slave has an individual address, which is not
volatile programmed. The address 0 may not be used, since every AS-i
slave has the address 0 on delivery and the address 0 is used at the AS-i
master for the function
automatic address programming
.
Each AS-i slave has a slave profile. The profile consists of 2 digits divided
by a dot. The I/O configuration is represented by the 1. digit, the ID code
(identification code) is represented by the 2. digit.
The direction of the data bits is described by the I/O configuration.
I: input, O: output, B: bidirectional
Slave profiles with the same I/O configuration where more near described
by the ID code.
An AS-i slave is connected to the two-wire-cable by means of the piercing
technique. Here the insulating material is penetrated by two piercing
connectors to get contact to the cable. Since the flat cable is mechanically
coded, there is a protection against reverse polarity. The replacement of
just mounted AS-i slaves is possible at any time. Here cables with self-
healing effect are available.
Due to the arbitrary network topology e.g. bus, star or tree each AS-i slave
may be mounted at any position within the network. Due to the small
frequency a termination at the end of the lines is not necessary. The line
length is limited to max. 100m. The line length may be increased up to
300m by means of a repeater.
What is AS-i ?
AS-i address
AS-i slave profile
Connection to AS-i
cable
