No. 20S071-02 4.5 External Control Specification SW board circuits for 3.5Φ stereo jack (External SW) Tip R1 1.8K R2 3.3K R3 4.7K R4 10K R5 27K GND 1 2 1 2 1 2 1 2 1 2 1 2 SW-A SW-B SW-C SW-D SW-E SW-F 3.5Φ stereo jack pin assignment for communication Tip Rxd Txd GND STC-HD213DV / STC-HD213DV-CS / STC-HD213SDI / STC-HD213SDI-CS / STC-HD213DVN / STC-HD213DVN-CS / STC-HD213SDIN / STC-HD213SDIN-CS Product Specifications and User’s Guide 14/94