Allen-Bradley’s 120 VAC 16-point block module is a Series B I/O module. It has two groups of 8 outputs which total to 16 outputs in a single block I/O module. The current rating is 300mA and voltage rating is 120 VAC. The frequency rating ranges from 47 to 63 Hertz. Important specifications for the 1791-0A16 include a maximum output voltage range between 20 and 132 VAC, a surge current that rates at 10 Amperes for 50 milliseconds, and a maximum output current range of 600 milliamperes for vertical mounting and 300 milliamperes for horizontal mounting. The 1791-0A16 has a minimum on-state current of 50 milliamperes per output and a maximum off-state leakage current of 3 milliamperes. The output signal delay for off to on is 1.0 millisecond at 60 Hertz and 1.0 millisecond at 50 Hertz. For on to off, the output signal delay is 8.3 milliseconds at 60 Hertz. Maximum on-state voltage drop is 1.5 Volts peak at 300 milliamperes. The external power of the 1791-0A16 limits at 85 to 132 Volts AC, 47-63 Hertz, and 150 milliamperes. The 1791-0A16 block I/O module requires an I/O scanner module to communicate with the SLC 500 controllers. The module is internally protected and hence does not require any external fuse.

The 1791-0A16 is compatible with PLC-2, PLC-3, PLC-5/20, and PLC-5 modules. The block I/O module has 16 point outputs but no single input. The design is compact and has built-in power supply. The module is easy to install. There are two switch assemblies. It can be accessed by uncovering the module. The status indicator helps with any issues or troubleshooting.

The Allen-Bradley 1791-0A16 has many general specifications to go along with it. This device is powered externally using an eighty-five (85) to one hundred and thirty-two (132) volt AC voltage at forty-seven (47) to sixty-three (63) hertz. Additionally, this external power source should have a current of one hundred and fifty (159) milliamperes. For this Allen-Bradley product, it has a maximum power dissipation of 16.9 Watts. The maximum thermal dissipation for this device comes in at 57.63 BTU per hour. This Series B I/O Module has a few different statistics when it comes to its isolation. First off, the isolation for the power supply to RIO is five hundred (500) volts alternating current. The isolation for I/O Group-to-Group is 1250 volts alternating current and the I/O Group-to-Logic is 1250 volts alternating current, as well. The wire sizes for the conductors of this particular product are a 14 gauge, or 2 mm², stranded maximum. Another conductor wire size is 3/64 inch insulation maximum. This Series B I/O Module has physical dimensions of 176.5 mm x 68.8 mm x 98 mm (H x W x D). Converted, these physical dimensions are 6.95 in. x 2.7 in. x 3.85 in. (H x W x D). The Allen-Bradley 1791-0A16 has many environmental conditions that one should take note of. For this device, the temperature range that is suitable for this device's operation is zero (0) to sixty (60) degrees Celsius, or 32 to 140 degrees Fahrenheit. When storing this device for any reason, the temperature range should stay within the range of negative forty (-40) to eighty-five (85) degrees Celsius, or negative forty (-40) to one hundred eighty-five (185) degrees Fahrenheit. The relative humidity around the device should be 5 to 95% non-condensing. 

The 1791-OA16 is manufactured by Allen-Bradley and is part of the 1791 Analog Block I/O Input/output Module family. The 1791-OA16 give operators access to a complete I/O interface. This interface includes the functionality of the I/O rack, adapter, power supply, and I/O modules. Measuring in inches, at 6.95H X 2.7W X 3.85D, the module is a compact, self-contained device. Each block module comes with two 8-position switches that are responsible for setting the starting I/O group, I/O rack number, communication rate, last chassis, last state, complementary I/O, input filter speed (for DC inputs only), and processor restart/lockout. The module comes with various indicator lights to alert the user to issues the 1791-OA16 is experiencing. The communication indicator specifies whether communication is occurring between the block module's scanner or processor. The 16 I/O indicators on the block module reflect the state of each individual input and/or output. The module scans both input and output data asynchronously and then transfers the data back and forth between the block module and the controller input and output image table. The 1791-OA16 can be used with several output devices. Typical output devices compatible include motor starters, solenoids, and indicators. The AC output circuits can drive AC loads with a maximum holding current of 300 mA/36 W and a maximum surge current of 10 A/1200 W at 60 degrees Celsius. There are certain modules, both AC and DC, input and output, that are compatible with the inverse 1771 series module under certain circumstances.