The 75x-655 AS-I Master connects AS-Interface systems to a higher-level fieldbus. This module acts as a master for the AS-Interface and as a slave for the fieldbus. The 75x-655 AS-I Master is a M4 master in accordance with the AS-Interface V3.0 Specification. This means: Up to 62 AS-Interface slaves can be connected per AS-I line Analog signal transfer is integrated in the master. All slave profiles are supported in compliance with V3.0. Combined 1–5 transaction types and acyclic write/read services are implemented. The AS-I functions are provided both cyclically and acyclically via the fieldbus. In cyclic data transfer, up to 32 bytes of I/O data are transferred for the AS-I line binary data. Free cyclic process image areas can be mapped with analog values. Furthermore, analog signals and all other commands and data of the new AS-I specification can be transferred in a management channel via the fieldbus. Diagnostics, which go far beyond the AS-I specifications, simplify the detection of both sporadic configuration errors and AS-I communication interferences. An auto-installation mode allows an AS-Interface network to be created via sequential slave installation, with no addressing tool required. Both signal transmission and operating status, as well as trouble-free local bus communication, are indicated via LEDs.
