The AB 1771-DL is a Gray code converter module. It requires a 12-24V DC power supply connected between the 1771-WB and the absolute encoder. The bulletin 845A-SJZ3DN6DW 8-bit Gray encoder is compatible with this module, along with the compatible 1771-WB wiring arm. The 8-bit gray code is then converted from an absolute encoder to an 8-bit binary number. This will then be used as an input to the AB programmable controller. While the gray encoder is in motion, the 120V AC zero-speed triac switch is on. The switch will only turn off after the module recognize that the motion has stopped at a selectable time delay. Using the trim pot located on the front of the module, the time delay can be modified between 0.3 and 6 seconds. Turn the knob counter-clockwise to decrease delay and clockwise to increase delay. The switch can be used when an encoder failure is detected because it will act as a safety interlock and open the drive circuit. Rated at 5A at 120V AC, the switch has an operating frequency of 47-63 Hz. The switch has 0.5A continuous output current and has 2A for 10 milliseconds surge current. Its switch has a minimum 50 mA load current and the ON-state voltage drop is 2V at 100 mA load current. The 1771-DL has a max 5 mA leakage current at OFF-state and the output fuse has an 8 AG at 1A normal blow. The module only receives inputs from the encoder that tracks a rotational position from 0-360 degrees. And this position values will be converted to an 8-bit gray code from 0-255. Using the multi-conductor cable, the encoder can send the coded position values to the 1771-DL module. The values will be placed at the backplane of I/O chassis of the module. The module will output an 8-bit 0-255 binary to the processor’s input through the backplane.


The module has estimated dimensions of 1″ x 6″ x 10″ (3 cm x 15 cm x 25 cm) and it weighs 0.43 kg. The keying will only work between pins 4 and 6 and between pins 24 and 26. The operating temperature is 32 – 140 degrees Fahrenheit. The module’s storage temperature is -40-185 degrees Fahrenheit with a 5 – 95% non-condensing relative humidity. The backplane current is 120 mA at 5V DC and 1 millisecond input filter time delay. The 1771-DL has a 6 mA per bit at 10V DC and 15 mA per bit at 27V DC on input sourcing current.