The EQUAD converts any clock source into optical encoder quadrature outputs. When up clock / down clock mode is selected (via DIP SW1) up-clocks generate an A leads B quadrature sequence and down clocks generate a B leads A quadrature sequence. Alternatively, DIP SW1 may be set for clock and direction inputs; each active edge of the clock input will advance or retard the quadrature output according to the level present on the direction input.
The EQUAD may be placed in-line between a clock source, such as a PLC or indexer, and will output TTL quadrature signals in response to rising or falling edges on its inputs. In situations where the clocks are generated by mechanical contacts such as switches or relays, an internal debounce digital filtering can be enabled with the DIP switch to debounce those signals and prevent multiple triggers. The filtering works by not recognizing a clock edge unless the level is stable for 9 milliseconds after the edge. The inputs have 5K Ohm pull-up resistors to +5V. The inputs can be driven with TTL levels, or open collector type outputs. The EQUAD samples its input at the crystal frequency of 3.58 MHz, which allows the circuit to respond to input frequencies in excess of 800 kHz in 1x mode, and 100 kHz in 4x mode.
Four DIP switches allow the EQUAD to select the input mode, trigger on rising or falling edges, output one or four quadrature state changes per trigger (x1 or x4 mode), and enable or disable the debounce feature.
DIP SW1 selects the input mode, either up clock / down clock, or clock / direction. DIP SW2 selects x1 or x4 mode. In x1 mode, a trigger will generate a single quadrature state change. In x4 mode, a single trigger will generate four quadrature state changes (a full encoder cycle). When in the x4 mode, the time period for each state change is 4.47 microseconds (13.4 microseconds for the full cycle). DIP SW3 optionally inverts the inputs so that a falling edge may be made the active edge. DIP SW4 enables the debounce feature.
The EQUAD draws its +5V power from either the input or output connectors. Connectors are 5-pin positive latching. DIN rail mounting is available.
- Cables and connectors are not included and must be ordered separately.
- US Digital warrants its products against defects in materials and workmanship for two years. See complete warranty for details.