AS‑Interface technology
The technical possibilities of AS-Interface technology are defined in a specification. Enhancements due to the technical development of AS-Interface technology are implemented in versions of the specification.
AS-Interface is optimized for the amount of data that meets the requirements of the lowest field level. The basic specification stipulates that up to 31 devices, each with 4 bits of digital input data and 4 bits of digital output data, can be connected to an AS-Interface network. The data is transmitted with a maximum cycle time of 5 ms.
An extension of the basic specification through an extended addressing mode enables the number of devices in a network to be doubled to 62 (A/B devices) and/or the transmission of larger data widths. The extensions, however, result in an increased cycle time for data transmission.
The AS‑Interface communication options from SEW‑EURODRIVE were developed based on the following specifications:
- AS-Interface Specification, Version V2.x (V2.0 and V2.1)
- AS-Interface Specification Version V3.0
The following table shows the version-dependent services of AS‑Interface. Since the versions are backwards compatible, only the most important extensions of versions V2.1 and V3.0 to version V2.0 are listed in the table.
Service | AS‑Specification | ||
|---|---|---|---|
Version V2.0 | Version V2.1 | Version V3.0 | |
Number of devices | Max. 31 | Max. 62 | Max. 62 |
Number of data bits for transmission of the DI/DO | 4 DI/4 DO | 4 DI/3 DO | 4 DI/4 DO |
Maximum cycle time for cyclic transmission of the DI/DO | 5 ms | 10 msThe respective cycle time for data exchange between the individual device and the master depends on the device profile and data width used and can be a multiple of the cycle time specified here. | 10 msThe respective cycle time for data exchange between the individual device and the master depends on the device profile and data width used and can be a multiple of the cycle time specified here. |
Analog value transmission | via function block | via device profiles | via device profiles |
Maximum data width for transmission of the AI/AO | 16 bytes for digital values and analog values | 124 bytes for analog values | 124 bytes for analog values |
Signals | Data and supply up to 8 A (depending on power supply unit) | Data and supply up to 8 A (depending on power supply unit) | Data and supply up to 8 A (depending on power supply unit) |
Medium | Unshielded, untwisted profile cable 2 x 1.2 mm² | Unshielded, untwisted profile cable 2 x 1.5 mm² | Unshielded, untwisted profile cable 2 x 1.5 mm² |
Cable length | 100 m, extension via repeater to max. 300 m | 100 m, extension via repeater to max. 300 m | 100 m, extension via repeater to max. 300 m |
For information regarding the data bits and cycle times used by SEW‑EURODRIVE inverters, refer to chapter Cycle times and data consistency of data transmission.
