NORD Drivesystems BU0135 - Manual (Page 49)

4 Commissioning
BU 0135 GB-2713 Pre-series version 49
4.3 AS Interface
4.3.1 The bus system
The ActuatorSensor Interface (AS-Interface) is a bus system for the lower field bus level. The transfer
principle is a single-master system with cyclical polling. Up to 31 standard slaves (or 62 A/B slaves in the
extended address range) can be operated on an unshielded two-wire cable up to 100m long and in any
network structure (tree / linear / star). For the AS-Interface, since the Complete Specification V2.1 a
differentiation is made between standard and A/B slaves. This version includes the doubling of the number
of slaves to 62. This is done by the double-assignment of addresses 1-31 and their designation as "A Slave"
and "B Slave". A/B slaves are labelled via the ID code and can therefore be uniquely identified by the
master.
Type SK 1x5E motor starters are A/B slaves, which correspond to slave profile S-7.A. They can be adminis-
tered by masters whose profile at least corresponds to class M4.
In contrast to devices with the profile S-7.0 devices with the profile S-7.A use the extended address range.
Devices with slave profiles S-7.0 and S-7.A can be jointly operated within an AS-i network as of version 2.1
(Master profile M4) with observance of the allocation of addresses (see example).
The AS Interface cable (yellow) transfers data and energy. Addressing is carried out via the master, which
also provides further management functions, or via a separate addressing device. The transfer of the 4 Bit
reference data (in each direction) is performed with effective error protection for standard slaves with a
maximum cycle time of 5ms. Due to the correspondingly higher number of participants, for A/B slaves the
cycle time (max. 10ms) is doubled for data which is sent from the slave to the master. Extended addressing
procedures for the transmission of data to the slave also cause an additional doubling of the cycle time to
max. 21ms.
The bus system is completely defined in the AS-Interface Complete Specification and is standardised as per
EN 50295, IEC62026.
Permissible
Standard slave 1 (Address 6)
A/B-Slave 1: (Address 7A)
A/B-Slave 2: (Address 7B)
Standard slave 2 (Address 8)
Not permissible
Standard slave 1 (Address 6)
Standard slave 2: (Address 7)
A/B-Slave 1: (Address 7B)
Standard slave 3 (Address 8)