Abstract: A standard hermaphroditic pneumatic glad-hand coupler includes a data bus connector containing a pair of contacts, each contact having an axis tangential to the arc along which the connector is carried during rotation of the coupler during establishment of a pneumatic connection. The pair of contacts can be in the form of a pair of hermaphroditic contacts, or one female and one male contact. In the female/male version, the female contact is surrounded on all sides except the mating and termination ends by an elastomeric dielectric projection and the male contact is situated in a pocket bordered by elastomeric dielectric material and arranged to receive the elastomeric dielectric projection when the male and female contacts are mated together upon coupling the glad-hand coupler with an identical glad-hand coupler so as to surround both contacts and also isolate the contacts from each other.