B&R X20PS4951 X20 Potentiometer Power Supply Module

Product Overview

The X20PS4951 (X20PS4951) is a specialized power supply module within the B&R X20 System, specifically designed to provide high-precision reference voltages for industrial potentiometers. This module features four independent output channels, each providing a stable $\pm10$ V supply to ensure accurate position or setpoint sensing. By providing a dedicated and short-circuit proof power source, the X20PS4951 eliminates the need for external voltage regulators when interfacing with manual controls or displacement transducers. It is widely applied in heavy machinery control panels, test bench systems, and specialized wood or metalworking equipment where analog setpoint adjustments are required.

Technical Configuration

The module architecture is engineered to provide isolated and protected reference voltages directly from the X20 backplane.

• Quad-Channel Supply: Equipped with four separate power supply units, allowing for the simultaneous operation of multiple potentiometers from a single slice.

• Precision Output: Delivers a stable $\pm10$ V output, compatible with standard industrial potentiometers ranging from $1$ k$\Omega$ to $10$ k$\Omega$ resistance.

• Integrated Protection: All channels are fully short-circuit proof, preventing damage to the X20 system if field wiring is compromised or a potentiometer fails.

• Galvanic Isolation: Provides electrical isolation between the output channels and the internal system bus, ensuring that field-side electrical noise does not interfere with the PLC's logic and communication.

Technical Specifications

FAQs

Can I connect a potentiometer with less than 1 k$\Omega$ resistance to this module?

No, the module is rated for a minimum resistance of $1$ k$\Omega$. Using a lower resistance would exceed the $20$ mA maximum load per channel, potentially triggering the internal protection or causing inaccurate voltage references.

Are the four channels isolated from each other?

While the channels are collectively isolated from the system bus, they are not isolated from one another. They share a common reference point within the module's field-side circuit.

What is the primary use case for the ±10 V output?

The $\pm10$ V supply is typically used to power the outer terminals of a potentiometer, allowing the wiper to return a signal that represents the full range of motion in both positive and negative directions, which is common in joystick and center-zero applications.

Engineering Installation and Wiring Standards

• Terminal Selection: The X20PS4951 requires a standard X20 12-pin terminal block (X20TB12). Ensure that the positive, negative, and common wires for each potentiometer are correctly assigned to the respective channel terminals to prevent cross-talk.

• Shielding for Precision: Since this module provides a reference for analog measurements, use shielded cables for the potentiometer wiring. The shield should be connected to the functional ground at the X20 shield terminal to prevent EMI from inducing "jitter" in the resulting analog signal.

• Load Calculation: Before commissioning, verify that the total current draw for all connected potentiometers does not exceed the module's rated $20$ mA per channel. For a $1$ k$\Omega$ potentiometer at $10$ V, the draw is $10$ mA, which is well within the safety margin.

• Maintenance and Diagnostics: Monitor the module status via B&R Automation Studio. If a short circuit occurs on the field side, the module will indicate a fault. Once the fault is cleared, the short-circuit proof outputs will automatically resume normal operation.