The 1753-OW8 relay output module is a distributed I/O module with 8 relay outputs developed by Allen-Bradley and Rockwell Automation. The module is intended for use with controllers from the GuardPLC series and it is suitable for use in industrial environments. Just like all the other modules for GuardPLC controllers, the 1753-OW8 was also carefully developed and manufactured with special attention paid to the safety features which were the top priority during this process. The underlying safety concept of the GuardPLC line of products is the fail-safe feature and the controllers’ CPUs that comply with the IEC 61508 (SIL 3) and ISO 13849-1 (PLe/Cat. 4) safety standards. The user can determine the safety time if faults that could lead to loss of safety functions occur. Also, the 1753-OW8 can be set to detect multiple faults within 24 hours. Should an error be detected, the controller could still work in a safe mode until the problem is solved. If any faults occur, including those related to Ethernet communication, all outputs are automatically switched off and are de-energized in a safe state.

The module is meant to be mounted horizontally and in spaces with unconstrained air flow. If the module is placed in tight spaces with no proper ventilation, the use of an additional fan is recommended. In addition, it should be noted that any other obstacles need to be installed at a distance of 100 millimeters (3.94 inches) minimum above and below the module. The terminal connections of the module fulfill the requirements of the IP20 protection standards and it can even meet the higher requirements if the 1753-OW8 is mounted in an enclosure. The 1753-OW8 incorporates a GuardPLC Ethernet interface through 2 RJ45/10/100BaseT ports with 100 Megabits per second and an integrated switch. The module operates on 24 Volts DC input voltage and it has a current consumption of 0.6 Amps for the maximum load. The approximate dimensions of the module include a width of 207 millimeters (8.14 inches), a height of 114 millimeters (4.49 inches) and a depth of 86 millimeters (3.38 inches). The module weighs around 1.3 kilograms (3.47 pounds). The environmental attributes include a temperature range of -40 and 85 degrees Celsius (non-operating) and a temperature range of 0 and 60 degrees Celsius when operating.