The TDD-C4 supports PWM and analog sensors with an option to automatically detect type. Features include a selectable units switch, three dc inputs for setup and operation, and asynchronous serial communications. TDD-C32 features include dc input for Zero and optional setup via serial or two-switch keypad.

Rapid Controls, 2693 Commerce Rd., Unit G, Rapid City, SD 57702, (605) 348-7688,