Functions Of The Board; Output Channels; Diagnostic - Addi-Data PA 1508 Technical Description

Chapter 7
7

FUNCTIONS OF THE BOARD

7.1

Output channels

The output channels can change their status according to the programmed data
bus information. The necessary data bus information is transmitted to the
corresponding driver function as a counter value (logic "1" or "0").
Logic "1"
means that the external supply voltage Vextern is connected to the output
channels on the 37-pin front connector.
Logic "0"
means that the external voltage is no longer supplied to the output channels
through the front connector.
Through the software functions the switching status of the outputs 1-8 can
parallelly be modified, as long as the watchdog is not in alarm status.
Function safety:
for an increased protection of the functions the user can enable the watchdog or
the diagnostic.
Safety through redundancy:
The control current circuitries of the outputs 1-4 and 5-8 are redundant: they are
controlled by the different operating drivers.
You detect if one of both drivers has run down or switched off:
- when the outputs 1-4 and 5-8 are so connected that a control function is only
enabled when both signals correspond.
Reset:
Driver:
7.2

Diagnostic

Both diagnostic signals are independent from one another and control each 4 outputs.
Diagnostic signal 1:
Diagnostic signal 2:
The diagnostic signal on the diagnostic pin of the front connector is an active
LOW signal. In normal operation the signal is set to high (0V ext.)
By overtemperature of a driver the corresponding channel switches off. The
signal on the diagnostic output is set to low within 100 ms.
Protection against overtemperature resets automatically when the chip
temperature falls under 125-140°C.
After reset the outputs are separated from the supply voltage.
The driver supports the following output functions:
- set one output and reset the others
- set one output without affecting the others
- reset one output
- set or reset parallelly and independently all outputs.
Analysis of the outputs 1 to 4
Analysis of the outputs 5 to 8
PA 1508
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