The Allen-Bradley 1771-OWNA module is a digital I/O module for PLC-5 controllers. It has 32 non-selectable normally-open contacts. The 1771-OWNA module uses electromechanical relays. The module is not approved by the UL or CSA standards for use with reactive loads. The 1771-OWNA module has 32 outputs split into 4 groups of 8. The module can be installed in slots A1B to A4B of an Allen-Bradley 1771 chassis. The voltage rating for the module is 24 to 138 Volts AC RMS and 24 to 125 Volts DC. The maximum current output per output is 1 Amp, which derates linearly by 0.333 Amps per degree Celsius at temperatures above 45 degrees Celsius. The maximum current output per module is 12 Amps which derates linearly at 0.4 Amps per degree Celsius for temperatures above 45 degrees Celsius.

The maximum current output per group on the 1771-OWNA module for 8 outputs is 4 Amps which derates linearly at 0.133 Amps per degree Celsius for temperatures above 45 degrees Celsius. The maximum power rating for the AC and DC outputs is 30 Watts per output. The minimum contact load is 10 milliamps. With all relays on the 1771-OWNA module of,f the power dissipation is 15 milliwatts and with all relays on, the dissipation is 12.5 Watts. The minimum thermal dissipation with all the relays off is 0.05 BTU per hour and the maximum thermal dissipation with all the relays on is 42.75 BTU per hour. The nominal and maximum backplane current ratings are 1.8 Amps and 2.5 Amps, respectively. The maximum length for the interconnect cable is 1000 feet. The operating temperature range for the 1771-OWNA module is from 32 to 140 degrees Fahrenheit.