ABB PS870A Bus Extension and Termination Board Advant OCS

ABB PS870A Bus Extension and Termination Board

Configured for signal termination and bus expansion in Advant OCS and MOD 300 systems, the ABB PS870A (PS870A Bus Extension and Termination Board) provides direct physical signal integrity management across system bus lines. The board facilitates the extension of the control bus to additional modules, ensuring that digital communication signals remain within specified voltage and impedance parameters. It serves as the physical interface for terminating system bus segments to prevent signal reflection within the control rack architecture.

Hardware Specifications

Industrial Control & Communication Velocity

The PS870A utilizes passive circuitry to maintain deterministic backplane bus communication velocity across expanded rack configurations. Within the Advant OCS and MOD 300 platforms, effective bus termination is mandatory to avoid bit-error rates caused by signal reflection at the end of the line. The board design supports I/O density scaling by providing a stable electrical bridge for additional I/O modules without exceeding the signal attenuation limits of the host bus. Technicians must verify that the termination resistance aligns with the impedance specifications of the specific system bus version to maintain data throughput consistency.

Frequently Asked Questions

Q: Can the PS870A be used to bridge different versions of the Advant OCS bus?

A: Compatibility is limited to specified bus architectures. Verify that the system bus topology and timing requirements match the PS870A design parameters before integration to avoid communication bus errors.

Q: Is it necessary to remove the PS870A when adding more modules to the bus?

A: When extending the bus, the PS870A may need to be moved to the final physical position on the bus segment to serve as the termination point. Ensure the final module on the chain provides the necessary termination.

Q: Does the board require an external power connection?

A: No. The PS870A is a passive termination and extension board that draws negligible power from the bus signals and backplane interface to perform its electrical termination function.

Field Installation Guidelines

• Bus Termination: Place the PS870A at the extreme physical end of the communication bus segment. Failure to terminate the bus correctly often leads to intermittent communication faults and data corruption.
• Cable Routing: Keep communication bus cables separated from high-voltage AC power wiring and variable frequency drive (VFD) output leads. Use grounded metallic cable trays to shield bus signals from electromagnetic interference.
• Mechanical Seating: Ensure the board is fully seated in the rack backplane connector. Use the integrated locking mechanisms to prevent the board from vibrating out of the backplane slot during machine operation.
• Connection Inspection: Routinely inspect the bus cable headers for signs of oxidation or mechanical fatigue, especially in environments exposed to corrosive gases or high levels of particulate matter.