Siemens SIMATIC ET 200SP Manual page 176

Glossary
AS-i slave with A/B address
AS-i slaves with A/B address use extended addressing. A (numerical) address can thus be
used by two slaves with A/B address, e.g., 1A and 1B. Based on the address organization,
up to 62 slaves with A/B address can be connected to the AS-Interface.
For cyclic data transmission, the master accesses each (numerical) address once per AS-i
cycle (max. 5 ms). If two slaves use a (numerical) address on the bus both as an A address
and a B address, two consecutive AS-i cycles are required for their data transmission (max.
10 ms rms). If a (numerical) address is used only as an A address or as a B address on the
bus, the data transmission for these slaves occurs in every AS-i cycle.
AS-i slave with standard address
Each AS-i slave with standard address occupies one address on the AS-Interface; based on
the address organization, up to 31 AS-i slaves with standard address can therefore be
connected to the AS-Interface. If a slave with standard address occupies an address, this
address is no longer available for slaves with A/B address.
For cyclic data transmission, the master accesses each address once per AS-i cycle (max. 5
ms).
CER
Configuration Error (Indication of configuration errors). The configuration error is indicated by
an LED if the actual bus configuration does not match the specified configuration.
CM
Communication module
Module for communication tasks that is used in an automation system as an interface
expansion for the CPU.
CPU
Central Processing Unit
176
AS-Interface master CM AS-i Master ST (3RK7137-6SA00-0BC1)
Manual, 07/2017, A5E02655262020A/RS-AD/004