Issue The STR-150 Installation Instructions state that the stat wires into D1, X1, and M of the Xenta 100 series controller. However, this is not applicable to the Xenta 121 and 122, which does not have a D1 input. Product Line TAC Vista Environment Xenta 122 STR-150 Cause The correct terminal for the mode input from the STR-122 is labeled differently on the Xenta 122 versus all other Xenta 100 series controllers. Resolution Wire the stat as follows: STR-150 Xenta 122 Label Terminal Label Terminal Mode 11 Y1 5 Data 12 X1 7 M 13 M 9 If you are looking for the wiring diagram for an STR-150 into a Xenta 121 the click here. The Purpose of output Y1 The only function that the STR-150 uses Y1 for is to get an effective occupancy signal from the Xenta 122. When the Xenta 122 is occupied, the man symbol will be displayed on the STR-150. If Y1 is already in use then the Status LED can be moved to a K output as explained is it possible to use an analog valve on the TAC Xenta 121-FC/HP and still have the effective occupancy active on the STR-150?. In order to activate this feature, the Hardwired status LED option must be selected. This can be found under the Configuration tab > Connected devices > Room unit in ZBuilder. If this feature is not desired then unselect Hardwired status LED and only wire up X1 and M. The STR-150 will still be able to send the controller the temperature, setpoint, bypass signal, and fan speed. ... View more