Allen-Bradley 1771-OFE1 PLC-5 Analog Output Module
The Allen-Bradley 1771-OFE1, also cataloged as the 1771-OFE1 Analog Output Module, operates as a dedicated hardware component for precision analog voltage/current signal generation within Allen-Bradley PLC-5 systems. It converts digital words from the system processor into 4 independent analog control signals with 12-bit conversion resolution to control field actuators, valves, and drive speed references.
Hardware Specifications
| Parameter | Specification |
|---|---|
| Model | 1771-OFE1 |
| Brand | Allen-Bradley |
| Origin | USA |
| Weight | 1.20 lbs (0.54 kg) |
| Dimensions | Standard 1771 Single-Slot I/O Module Form Factor |
| Operating Temp | 0 to 60 deg C |
| Power Consumption | Backplane bus power + external loop supply |
| Module Type | Analog Output Module |
| Output Count | 4 Points |
| Resolution | 12 Bit |
| Signal Types | Analog Current / Voltage Output Ranges |
Backplane Bus Communication Velocity & I/O Density Scaling
The 1771-OFE1 utilizes block transfer read/write (BTR/BTW) operations across the 1771 backplane to transfer multi-channel analog output data without degrading backplane bus communication velocity. Internal digital-to-analog converters deliver continuous 12-bit signal conversion, ensuring linear control accuracy across all 4 isolated output channels. Digital filtering and channel-to-backplane galvanic isolation prevent field noise, earth loops, and electromagnetic interference from disturbing system processor logic.
Frequently Asked Questions
Q: How is output data transferred between the PLC-5 processor and the 1771-OFE1 module?
A: Data transfer is executed via Block Transfer Write (BTW) instructions configured in ladder logic, transferring digital values to the module's 12-bit output channels.
Q: Are individual output channels on the 1771-OFE1 isolated from backplane logic?
A: Yes, the module incorporates optoelectronic isolation between the internal backplane logic bus and the field-side analog output circuitry.
Field Installation Guidelines
- Backplane Slot Alignment: Verify chassis keying plastic bands are positioned per 1771-OFE1 requirements, then slide the module into the assigned 1771 chassis slot until fully seated.
- Signal Cable Shielding: Use individually shielded twisted-pair conductors for analog signal lines. Connect shield drain wires to chassis earth ground at one end only to prevent ground loops.
- External Power & Wiring: Connect the field power supply and analog output conductors to the designated wiring arm, ensuring correct polarity for current or voltage loops before locking the wiring arm into place.
Allen-Bradley 1771-OFE1 PLC-5 Analog Output Module
Allen-Bradley 1771-OFE1 PLC-5 Analog Output Module
The Allen-Bradley 1771-OFE1, also cataloged as the 1771-OFE1 Analog Output Module, operates as a dedicated hardware component for precision analog voltage/current signal generation within Allen-Bradley PLC-5 systems. It converts digital words from the system processor into 4 independent analog control signals with 12-bit conversion resolution to control field actuators, valves, and drive speed references.
Hardware Specifications
| Parameter | Specification |
|---|---|
| Model | 1771-OFE1 |
| Brand | Allen-Bradley |
| Origin | USA |
| Weight | 1.20 lbs (0.54 kg) |
| Dimensions | Standard 1771 Single-Slot I/O Module Form Factor |
| Operating Temp | 0 to 60 deg C |
| Power Consumption | Backplane bus power + external loop supply |
| Module Type | Analog Output Module |
| Output Count | 4 Points |
| Resolution | 12 Bit |
| Signal Types | Analog Current / Voltage Output Ranges |
Backplane Bus Communication Velocity & I/O Density Scaling
The 1771-OFE1 utilizes block transfer read/write (BTR/BTW) operations across the 1771 backplane to transfer multi-channel analog output data without degrading backplane bus communication velocity. Internal digital-to-analog converters deliver continuous 12-bit signal conversion, ensuring linear control accuracy across all 4 isolated output channels. Digital filtering and channel-to-backplane galvanic isolation prevent field noise, earth loops, and electromagnetic interference from disturbing system processor logic.
Frequently Asked Questions
Q: How is output data transferred between the PLC-5 processor and the 1771-OFE1 module?
A: Data transfer is executed via Block Transfer Write (BTW) instructions configured in ladder logic, transferring digital values to the module's 12-bit output channels.
Q: Are individual output channels on the 1771-OFE1 isolated from backplane logic?
A: Yes, the module incorporates optoelectronic isolation between the internal backplane logic bus and the field-side analog output circuitry.
Field Installation Guidelines
- Backplane Slot Alignment: Verify chassis keying plastic bands are positioned per 1771-OFE1 requirements, then slide the module into the assigned 1771 chassis slot until fully seated.
- Signal Cable Shielding: Use individually shielded twisted-pair conductors for analog signal lines. Connect shield drain wires to chassis earth ground at one end only to prevent ground loops.
- External Power & Wiring: Connect the field power supply and analog output conductors to the designated wiring arm, ensuring correct polarity for current or voltage loops before locking the wiring arm into place.
