The DN-DO-16DR-A & DN-DO-16DR-B are termination boards with relay (Form C, SPDT) output. The DN-DO-16DR-A is used for digital output channel 0~15, and the DN-DO-16DR-B is used for digital output channel 16~31. These boards offer 2 output for each channel to extend control logic due to the Form C relay, it can be positive (N.O.) or negative (N.C.) logic output or both. In addition, each channel is built-in two varistors on N.O. and N.C. channel to protect against high-voltage transients and surges to the control loop.