- Specific to model 2115 and earlier.
- Located in the #4 slot.
- Routes the stimulus to the switching bays.
- Works in tandem with the relay driver board mounted within the chassis.
- Output stimulus is routed off the top connectors.
- Return signals routed through the middle and lower-right connectors.
Source: NETS User Manual, Revision D, document 132-06035-0006, section 10.2.4.