1794-APB

The Allen-Bradley 1794-APB is a part of the Flex I/O system that functions as a communication adapter. Specifically, this module is a ProfiBus adapter module that is primarily used to communicate with Profibus master devices, including Programmable Logic Controllers (PLC) mainly for I/O data exchange, enabling implementation of distributed I/O architecture. The 1794-APB acts as the communication bridge between the Flex I/O modules and the PLC which may be ControlLogix, CompactLogix, SLC 500 and PLC-5 control systems. It connects the flex I/O module through a Profibus link with transmission speed of up to 12 Mbps. This communication adapter supports installation of up to Eight (8) Flex I/O modules and powered by an external supply voltage of 24 VDC, nominal and 19.2 - 31.2 VDC input voltage range. The 1794-APB comes with LED status indicators including STATUS LED indicating the module’s operational state and PROFIBUS LED for indicating network activity. Under normal condition, these LED are lit Green; when abnormal condition is sensed by the module, RED light is triggered. The 1794-APB has a backplane current draw of 640 mA @ 5VDC with maximum power consumption of 400 mA from external power supply. It also has a power dissipation of 7.68 Watts @ 19.2 VDC and Thermal Dissipation of 26 BTU/hr @ 19.2 VDC. The 1794-APB supports DIN rail mounting. It is required that a highly conductive DIN rail is used as this mounting hardware connects the 1794-APB to the grounding system. Never use DIN rail that is made of poor conducting materials or highly susceptible to oxidation and corrosion.

The Allen-Bradley 1794-APB is a FLEX I/O 12 Mbps PROFIBUS DP network adapter module. It is a communication adapter that can power the internal logic of up to 8 input or output modules in one FLEX I/O system. The 1794-APB communicates with the FLEX I/O backplane and any PROFIBUS DP master/scanner controller within the PROFIBUS DP network. It is also a slave device to the DP master/scanner and to the master controller of the FLEX I/O system it is part of. It supports communication rates such as 57.6 Kbps, 115.2 Kbps, and 230.4 Kbps. This adapter module uses a standard PROFIBUS drop cable and a 9-Pin D-shell PROFIBUS connector. It has an open-type enclosure and can mount on a panel or a DIN rail. The 1794-APB adapter module measures 3.7 x 3.6 x 3.4 inches and has two diagnostic indicators where users can check the device’ status (labeled STATUS) and the communication link status (labeled PROFIBUS). The input voltage range of the 1794-APB adapter module is 19.2 to 31.2 Volts DC, including an AC ripple of 5%. It has a maximum input current of 450 mA and 330 mA at 24 Volts DC, as well as a nominal input voltage of 24 Volts DC. The 1794-APB adapter module has a maximum FlexBus output current of 640 mA at 5 Volts DC and an inrush current of 23 Amps for 2 milliseconds. Its power consumption is 7.9 Watts at 24 Volts. The isolation voltage of this adapter module has been 100% tested for 1 second at 850 Volts DC between the user power and FlexBus. It also has a maximum power dissipation of 7.68 Watts at 19.2 Volts DC and a thermal dissipation of 26 BTU/hour at 19.2 Volts DC also. Its operating temperature range is 0 to 55 degrees Celsius, its storage temperature is -40 to 85 degrees Celsius, and its maximum surrounding air temperature is 55 degrees Celsius.