The 3-pin (m) connectors supply power for active probes.
Top Pin: Ground
Left Pin: +15 VDC ±2%, 400 mA maximum; protected by PTC @0.5A
Right Pin: –12.6 VDC ±5%, 300 mA maximum; protected by PTC @0.5A
(PTC=slow acting, automatically resettable fuse)