Labels:text | diagram | screenshot | technical drawing OCR: ST 3144 Family Installation Guide, Rev D pg 9 1 2 3 4 PCB Available External LED Connector + 5 VDC + 5 Volts Return +12 Volts Return +12 VDC 4-Pin DC Power FRONT Drive Activity LED 40-Pin Ground AT Interface 10-Pin Connector User Configuration Block 3-Pin DC Power FRONT Keyway - PCB 6 8 10 Drive is Ground Master ·+12 VDC Slave + 5 VDC Present Key - Pin 20 removed Active LED Reserved (DO NOT USE) Keyway Reserved Pin 1 (DO NOT USE) Figure 1: AT jumpers and connectors