Agilent Technologies 78581B - SDN Bedside; Verify Proper Operation of Priority Wires

SDN and ACC System Level Troubleshooting
3-15
Verify Proper Operation
of Priority Wires
With the ACC running and the instruments connected to the branch,
measure the priority wire voltage from the downstream connector on the
last instrument—most downstream instrument—on the branch as indicated
on the following connector pins. Refer to the connector pin illustrations
shown in Figure 3-6.
MEASUREMENT NOMINAL VOLTAGE
MEASURED WITH DVM
PIN C (±)——to——PIN B (–) =
≥
3.0V
PIN C (±)——to——PIN D (GND) =
≥
0.6V
PIN B (–)——to——PIN D (GND) =
≥
3.6V
PIN C (+)——to——PIN A or PIN E =
∞
PIN B (–)——to——PIN A or PIN E = ∞
SDN Bedside:
PIN A (±) ----------------> DATA WIRE — PINK (positive)
PIN B (–) ----------------> PRIORITY WIRE — BLACK (negative)
PIN C (+) ----------------> PRIORITY WIRE — GRAY (positive)
PIN D (GND) ----------------> DRAIN WIRES — GROUND
PIN E (–) ----------------> DATA WIRE — BLUE (negative)