S-DIAS ANALOG MIXED MODULE ±10 V AM 441
26.07.2023 Page 31
10 Expanded Timing Modes (FW version ≥ V02.00)
The AM 441can operate the analog inputs in either speed mode (highest possible scan
rate) or in time-offset mode (measuring active only once per cycle at a defined time). This
can be configured via bit 3 in the Info byte of the configuration data (address 0x0104).
The analog outputs on the contrary, are always operated in time-offset mode. By default
however, predefined time offsets (at the start of a cycle) are used for this purpose. By set-
ting bit 4 in the Info byte of the configuration data (address 0x0104), the time offsets can
also be predefined for the analog outputs of the HW class.
Thereby, it is important to note that the time offsets for the analog outputs can only be ex-
actly stopped when the analog inputs are also operated in the same operating mode, since
they are assigned to the analog outputs. If the analog inputs should be operated in speed
mode, the actual time point of the defined analog value output can deviate up to 200 µs.
10.1 Speed Mode
The speed mode is available for the analog inputs only. In this mode, the analog inputs are
scanned as fast as possible and filtered to achieve the highest possible sampling rate. The
time point of the individual measurements cannot be defined since measuring is continuous
and is therewith performed several times per S-DIAS cycle.
The analog outputs are activated during the sections of free time between measurements of
the analog inputs. A constant sampling rage is thereby guaranteed.
10.2 Time-Offset Mode
The time-offset mode is basically used for the analog outputs, since they must be written
only once per S-DIAS cycle. However, it also available for the analog inputs (the appropri-
ate bit must be set in the info byte of the configuration data).
In the time-offset mode, the analog in and outputs (depending on the configuration of both
or only the outputs) are measured only once per cycle (the duration of a cycle corresponds
to the S-DIAS cycle time). The measurement or output time can be defined in µs as an
offset to the S-DIAS Sync (cycle start point).
The time for the analog inputs are thereby predefined by the hardware class directly (in the
cyclic data for the Firmware. A time offset can be set per channel)
In the analog outputs, predefined time offsets configured so they correspond to the earliest
time possible are used by default.
If however, bit 4 in the info byte of the configuration file (Address 0x0104) is set, the offsets
in the cyclic data provided by the HW class are used. Here, it is important to note that de-
viations can occur if the analog inputs are operated in speed mode.
The settable values (time offsets) are subject to the following limits:
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