DAS Backplane LEDs and Test Points

1 LEDs

MDAS 16 LEDs are located on the Right Backplane. Low Z FET lines are set the same as Data FET lines in the current implementation.

Figure 1. MDAS 16 LEDs (as viewed with DAS at 12 o’clock)

2 Power Supply Test Points

Test Points are available on the Center Backplane to measure Power Supply voltages.

Figure 2. MDAS 16 Center Chassis Power Supply Test Points

3 Detector Bias Test Points -5v_A (DVSS)

The MDAS16 backplanes have limiting resistors (392 ohms nominal) between the DVSS (-5V_A) supply and the Detector flex module connections. These resistors limit the current to prevent the backplane traces from fusing in the case of a short on the DDIF.

Each distinct backplane has been divided up into 4 groups of modules, each group having its own limiting resistor and test point. This is to make finding the shorted module easier. Each test point is referenced to the DAS center chassis TP 4 AGND test point.

Figure 3. Left Backplane DVSS (-5v_A) Zone Coverage

Figure 4. Center Backplane DVSS (-5v_A) Zone Coverage

Figure 5. Right Backplane DVSS (-5v_A) Zone Coverage