Product Description

The X20DC137A is a modern B&R module that supports a differential ABR encoder that samples incrementally. The incremental ABR encoder for this digital counter module needs a terminal voltage of 24 volts and performs evaluation 4 times with an input frequency of 300 kHz and counter size of 16/32-bit. During operation, the ABR incremental encoder has a minimum slew rate of 1 V per microsecond and takes in a maximum internal supply of 600 mA. The X20DC137A monitors the encoder inputs and classifies them accordingly. Aside from the incremental ABR encoder, this digital counter module also supports two additional inputs, mainly for latch purposes.

The X20DC137A's two digital inputs have an input voltage range of 20.4 to 28.8 V. The digital input circuits are classified as sinks and allow a maximum current of 3.3 mA to flow at a rated terminal voltage of 24 V. Like other digital counter modules, the digital inputs use 3-wire connections and have a switching threshold of 5 V for low signal and 15 V for high signal. The input channels have an estimated input resistance of 7030 ohms. The digital input channels are not isolated from each other but are separated electrically from the X20DC137A's main bus.

During operation, the X20DC137A consumes a total of 1.21 watts, 1.20 W of which is contributed by the internal I/O. The signal lines for this digital counter module come with shields, increasing immunity against external RFI, EMI, or other noises. The X20DC137A has a recommended installation spacing of 12.5 millimeters, permitting a 0.2 maximum measurement error. To utilize this digital counter module, separate X20 bus modules and terminal blocks must be purchased.