Is Your Legacy Control System Holding You Back?
Many plant engineers face a common challenge: a reliable Allen-Bradley POINT I/O system that cannot communicate with a PROFIBUS network. The 1734-APB solves this problem directly. This adapter module bridges the gap between your existing POINT I/O modules and a PROFIBUS DP master. It allows you to modernize your network without replacing your entire I/O infrastructure. This is the smart upgrade path for legacy systems.
What Is the 1734-APB?
The Allen-Bradley 1734-APB is a PROFIBUS DP Network Adapter from the POINT I/O series. It acts as a dual-role device. On the POINTBus backplane, it functions as a master unit. It communicates with up to 63 POINT I/O modules. On the PROFIBUS network, it serves as a slave unit. It exchanges I/O data with a PROFIBUS master. This dual functionality makes it a critical gateway in mixed-vendor automation environments.
Key Technical Specifications
The 1734-APB operates on a 24 Volts DC nominal input, with a range of 10 to 28.8 Volts DC. It provides 400 milliamps of field side power. The inrush current reaches 6 amps maximum for 10 milliseconds. It delivers 1000 milliamps of POINTBus current at 5 Volts DC. Power consumption is 8 Watts, with 2.8 Watts dissipated at 28.8 Volts. Reverse polarity protection safeguards the input. During power interruptions, the output holds within specifications for 10 milliseconds at 10V with maximum load. These specs ensure stable operation in demanding industrial settings.
Upgrade Path and Compatibility
Replacing an older adapter with the 1734-APB is a cost-effective upgrade. It integrates seamlessly with existing POINT I/O modules. You can connect up to 63 modules, which supports significant system expansion. The adapter converts 12 to 24 Volts DC field power to 5 Volts logic power. It can power up to 14 I/O modules with a maximum of 10 Amps of field power. For compliance, use a Safety Extra Low Voltage (SELV), NE Class 2, or Protected Extra Low Voltage (PELV) power supply. This flexibility simplifies integration with various control panels.
Installation and Setup
Install the 1734-APB at the left side of a 1734 system. This position allows it to manage the POINTBus backplane efficiently. Ensure the input voltage stays within the 10 to 28.8 Volts DC range. Verify that the field power supply meets the SELV, NE Class 2, or PELV requirements. The adapter’s reverse polarity protection prevents damage from wiring errors. Always follow local electrical codes during installation. Proper grounding and shielding are essential for PROFIBUS network reliability.
Maintenance and Reliability
The 1734-APB has no moving parts, which minimizes wear. Schedule periodic inspections to check for loose connections and environmental contaminants. Verify that the input voltage remains stable. Monitor the power dissipation to ensure adequate ventilation. The 2.8 Watts dissipation at 28.8 Volts is modest, but enclosures must still allow heat to escape. In dusty environments, use filtered enclosures. These practices extend the adapter’s service life and maintain ROI.
Frequently Asked Questions
What is the maximum number of POINT I/O modules the 1734-APB can support?
The adapter supports up to 63 POINT I/O modules on the POINTBus backplane.
Can the 1734-APB handle reverse polarity on the input?
Yes, it features reverse polarity protection for input overvoltage.
What is the POINTBus output current of the 1734-APB?
It provides 1000 milliamps (1 Amp) at 5 Volts DC.
How long does the output hold during a power interruption?
The output stays within specifications for 10 milliseconds at 10V with maximum load.
What power supply types are recommended for the 1734-APB?
Use a SELV, NE Class 2, or PELV power supply to comply with CE Low Voltage Directives.
