Analog input module DSCA45

TTLvoltagecurrent

Each DSCA45 frequency input module provides a single channel of frequency input which is isolated and converted to a standard analog voltage or current output. The frequency input signal can be a TTL level or zero-crossing signal. Terminal 7 (-IN) on the field-side terminal block is the "common" or ground connection for input signals. A TTL signal is connected from terminal 6 (+IN) to terminal 7 (-IN), while a zero-crossing signal is connected from terminal 5 (+EXC) to terminal 7 (-IN). Input circuitry for each of the signal types has hysteresis built in. An input signal must cross entirely through the hysteresis region in order to trigger the threshold comparator. A +5.1V excitation is available for use with magnetic pick-up or contact-closure type sensors. The excitation is available on terminal 8 (-EXC) with return at terminal 7 (-IN). The DSCA45 frequency input module output is either voltage or current. A dedicated loop supply is provided at terminal 3 (+OUT) with loop return located at terminal 4 (-OUT) for all current output models. The system-side load may be either floating or grounded.