Abstract: A two way digital communication arrangement utilizes a CATV system to provide bidirectional data transport service between any two points within the CATV system. The headend receives an upstream message and selectively rebroadcasts such message on the downstream portion of the spectrum. System intelligence is thus distributed throughout the system as server and subscriber nodes can be located anywhere in the CATV network. In order to obtain access to the CATV communication resources, user equipment at each node must attach a frame verifier (FV) code to each respective message. The headend examines the FV and permits rebroadcast of messages only if the FV code indicates that the user is authorized.

Abstract: Apparatus for withdrawing a liquid such as oil from a container such as the crankcase of an engine comprising a rigid, fluid-tight receptacle having a circular top wall and an upstanding rim at the periphery thereof, a vacuum line extending from the receptacle for connection to a source of vacuum and having a check valve for preventing backflow of gas, an elongated flexible probe for insertion into the container to take up the liquid, and a conduit divided into two portions and extending from the receptacle to the probe. The first conduit portion extends from the receptacle to a control valve, and the second conduit portion has one end connected to the probe and the other end adapted for selective attachment to and detachment from the control valve.