HEIDENHAIN TNC 306 Service Manual - Manual (Page 27)

SERVICE MANUAL TNC 306/360
Page 23
HEIDENHAIN Service
6.3 Connectors on the Keyboard Units TE 355 A/B
6.3.1 Connector Designation: TE 355 A/B
TE 355 A (tall version)
TE 355 B (wide version)
(X1 is not used)