Overview
The Opto 22 PB4R is a G1 4-channel isolated output-only mounting rack engineered for industrial automation systems requiring isolated digital output control. The PB4R output mounting rack holds four G1 digital output modules (outputs only) and features isolation between channels. This classic mounting board is commonly found in legacy control systems where barrier strip field connections and channel isolation are critical for system reliability.
Key Features
- Four-Channel Capacity: Mounting racks have been professionally designed to accommodate up to 4 single channel digital or standard analog I/O modules in any combination.
- Full Channel Isolation: Channel-to-channel isolation is accomplished by not having any common connections between channels on either the logic side or the field side of the mounting rack.
- Mixed Logic Voltage Support: It can be used with 5 V, 15 V, and 24V logic and is often used to interface different families of logic.
- Barrier Strip Connections: This rack is ideal for applications that require barrier strips on both the field and logic sides.
- Logic Polarity Flexibility: The rack is compatible with both positive-true logic and negative-true logic computer I/O ports.
- RoHS Compliant: ROHS COMPLIANT: YES
Technical Specifications
Comprehensive specifications for integration into automation control systems:
- Module Capacity: 4 channels (output-only)
- I/O Generation: G1 (Standard, Generation 1)
- Channel Isolation: Yes (field and logic sides)
- Supported Logic Voltages: 5 VDC, 15 VDC, 24 VDC
- Logic Polarity: Positive-true and negative-true
- Barrier Strip Type: 6-32 screw terminals (field and logic sides)
- Operating Temperature: 0 to 70°C (32 to 158°F)
- Humidity: Up to 95% relative humidity, non-condensing
- Dimensions: 4.5 × 3.5 inches (114.3 × 88.9 mm)
- Thickness: 2.2 inches
- Weight: 0.42 lbs
- Interface: 4-pin connector
Typical Applications
The PB4R mounting rack is well-suited for legacy and modern industrial control scenarios:
- Interfacing multiple logic families (5V PC logic to 24V PLC logic)
- Industrial process control with isolated field outputs
- Machine automation requiring channel-to-channel isolation
- Retrofit and modernization of existing control systems
- Applications requiring mixed logic voltage on a single rack
- Systems using barrier strip field wiring and screw-terminal connections
Compatibility & Replacements
Compatible With
- Opto 22 G1 digital output modules (single-channel, output-only)
- Programmable logic controllers (PLCs) with 5V, 15V, or 24V logic outputs
- Industrial PCs and legacy control systems requiring isolated output control
- Systems using barrier strip terminal connections for field wiring
- Legacy Optomux, PAC, and SNAP controller ecosystems
Replaces / Drop-In Replacement For
The PB4R is a standard mount for G1 modules. Verify module compatibility with your system integrator before ordering. This board does not accept dry-contact output modules or newer G4-series modules.
Works With
- Opto 22 G1 I/O family (digital and analog output modules)
- Barrier strip screw-terminal field connections
- 4-pin connector control-side interface
- Legacy Opto 22 automation control platforms












