Details of the operating phases

Offline

After power-on, the AS-i master goes into offline mode, i.e. there is no communication with the AS-i slaves.

During normal operation, the AS-i master can be put into offline mode (OFFLINE-flag is set) via the process data. The output data of all activated AS-i slaves are set to default value 1_bin, and the input data of all activated AS-i slaves are set to default value 0_bin. The AS-i master is then in offline mode and will send no further AS-i commands.

As soon as the OFFLINE flag is no longer set, the AS-i master copies the new list of currently projected slaves from parameters 0x58 and 0x59 to parameters 0xA8 and 0xA9 (LPS) and automatically returns to the detection phase. If an AS-i slave in the list of currently projected slaves (LPS) is activated, the AS-i master operates in protected mode (PRJ_ACTIVE flag is set in the process data ), otherwise it operates in configuration mode (PRJ_ACTIVE flag is reset in the process data).

Start-up

Detection phase

During the detection phase the I/O ID and ID codes of all AS-i slaves are queried and entered in parameters
- 0x90 to 0x97 (read I/O IDs) or
- 0x98 to 0x9F (read ID codes),
- 0xD0 to 0xD7 (read extended ID codes 1) and
- 0xD8 to 0xDF (read extended ID codes 2).

All AS-i slaves that were found are entered in the list of detected AS-i slaves (LDS, parameters 0xB0 and 0xB1). The AS-i master will only enter the activation phase once at least one slave was detected or found.

Activation phase

In protected mode, the AS-i master activates only the projected AS-i slaves from the list of currently projected slaves (LPS, parameters 0xA8 and 0xA9).

In configuration mode, all AS-i slaves that were found during the detection phase are activated. To this end, the AS-i master sends a parameterization request (activation parameter, parameters 0x50 to 0x57) and a data request (with default values 1_bin as outputs). All activated slaves are entered in the list of activated slaves (LAS, parameters 0xB8 and 0xB9). Once all AS-i slaves have been processed, the AS-i master automatically enters the data exchange phase.

Normal operation

Data exchange phase

During the data exchange phase, the AS-i master exchanges data with each activated AS-i slave. If an AS-i slave does not respond in three consecutive data exchange phases, it is removed from the LAS and the LDS, and its inputs are set to the default value 0_bin. Once a data cycle has been completed with all activated AS-i slaves, the AS-i master enters the management phase.

Management phase

During the management phase, an AS-i command is sent if an operating address is to be set via automatic address programming, or if an AS-i command was requested via the AS-i command interface (parameter 0x100). Otherwise the AS-i master enters the inclusion phase without issuing an AS-i command.

Inclusion phase

During the inclusion phase, only one command is sent. The system will attempt to find and activate new AS-i slaves, and the respective status is updated accordingly. The steps are the same as during the recognition or activation phase, except that they are now distributed over up to seven cycles.