Rockwell Automation T8403 Trusted 24V dc Digital input Module - 40 Channel - Manual (Page 25)

Trusted
TM
Module T8403
Issue 15 Jun 13 PD-T8403 25
4.3. I/O Status LEDs
There are 40 input channel status LEDs on the module front panel, one for each field input. These
indicators are controlled by the FPU. The FPU receives data from each of the module slices. The
FPU performs a 2-oo-3 vote on each data bit from the slices and sets the indicators accordingly.
The input status LED mode is dependent upon the voltage level of the field I/O signal. Each field input
voltage is measured and compared to six threshold levels (four configurable and two fixed) which
produce seven threshold bands. Each threshold band can be defined to have a particular indicator
mode: off, green, red, flashing green, or flashing red.
The configurable voltage thresholds and LED modes allow users to customise the input measurement
and status indications to suit individual application requirements. Without customisation, the default
indicator modes are suitable for digital inputs without line monitoring as described below:
Indicator State Description
Off Open field switch (contact) or open circuit or indeterminate
between open and closed (states 1,2,3).
Green Closed field contact (contact) or short circuit (states 4,5).
Red – flashing Channel Fault (state 7).
Table 17 Default I/O status Indicators
Note: The LEDs indicating channel status may be configured to suit user requirements by
implementing the procedure for configuring the System.INI file detailed in PD-8082B.