GF82.00-P-2001Q Wake-Up, Function

GF82.00-P-2001Q Wake-Up, Function

Normal wake-up
Since the transmitting and receiving diodes and the chip of the digital data bus system (D2B) are automatically shut off if they are not needed (sleep mode), a wake-up pulse, which activates the system, is required to start a new data transfer. This is accomplished via the separate wake-up line. For this purpose, the master unit actuates the wake-up signal (electrical signal), which allows the voltage in the wake-up line to decrease to a defined value. The chip of the digital data bus system (D2B) in the components recognizes on account of the duration of the signal that this is a wake-up signal, and the digital data bus (D2B) is then activated. The digital data bus (D2B) is thus then in activated state. A "wake-up" can take place in a quiescent system (sleep mode) even without the wake-up pulse of the master unit by activation of a component located at the digital data bus (D2B).

Wake-up diagnosis
For diagnosis of the wake-up circuit in the communication components, the master unit can trigger a wake-up diagnosis signal using the data link connector (X11/4) with STAR DIAGNOSIS. This signal differs from the wake-up signal by the fact that it has a significantly longer duration. The communication components react to this long wake-up pulse with a signal on the wake-up line (message to master unit). This allows the master unit to recognize which components have received the long wake-up pulse. The wake-up diagnosis signal can only be actuated when the digital data bus (D2B) cannot be activated due to an error. If all components reply to the master unit, then their voltage supply is OK.