Functions of the board APCI-3xxx
(standard)
44
Fig. 8-4: Wiring of the analog ground lines (voltage version)
8.4
Digital inputs
The inputs are designed for the acquisition of external signal states: The
input information is loaded as numerical value into a memory unit of the PC
by software.
This numeric value calculates the state of the inputs signals.
24 V optically isolated inputs
They correspond to the 24 V industrial standard (IEC1131-2):
-
logic"1" corresponds to an input voltage superior to 19 V
-
logic"0" corresponds to an input voltage inferior to 14V.
The current consumption for each input is 10.5 mA (when nominal voltage).
The max. input voltage is 30 V.
The inputs signals are filtered by TRANSIL diodes, Z diodes, LC filer and
optical couplers. Herewith the impacts of inductive and capacitive incoupled
interferences are reduced.
The board has not to be initialised in order to read directly the digital
information of the inputs. The data can be read right after Power ON.
Fig. 8-5: Input circuitry
