Allen-Bradley 1771-OAN 1771 Digital AC Output Module
Configured for high-density AC load switching in Allen-Bradley 1771 I/O chassis, the Allen-Bradley 1771-OAN, also cataloged as the 1771-OAN Digital Output Module, provides direct physical/electrical execution. It handles discrete control signal routing across 32 isolated AC solid-state output points. The module interfaces directly with standard field-side AC actuators, motor starters, solenoids, and indicators via the system backplane without requiring interposing relays.
Hardware Specifications
| Parameter | Specification |
|---|---|
| Model | 1771-OAN |
| Brand | Allen-Bradley |
| Origin | USA |
| Weight | 2.95 lbs (1.34 kg) |
| Dimensions | Standard 1771 Single-Slot I/O Module |
| Operating Temp | 0 to 60 deg C |
| Power Consumption | Backplane Current: 300 mA at 5 VDC |
| Output Points | 32 points (4 isolated groups of 8) |
| Voltage Range | 80 to 265 VAC |
| Nominal Voltage | 120 to 240 VAC |
| Output Current per Point | 1.0 A at 30 deg C / 0.3 A at 60 deg C |
| Output Current per Group | 2.0 A at 30 deg C / 0.6 A at 60 deg C |
| Output Current per Module | 8.0 A at 30 deg C / 2.4 A at 60 deg C |
Backplane Bus & Deterministic I/O Execution
The module interfaces with the Allen-Bradley PLC-5 system via the 1771 parallel backplane bus architecture. Deterministic I/O data processing is maintained by synchronized backplane scan cycles, transferring 32-bit output status words directly from the processor image table. Advanced optical isolation protects internal backplane logic components from field-side voltage transients up to 1500 VAC. Signal routing, output state latches, and power switching circuitry are partitioned across four independent electrical groups, mitigating total module loss in the event of localized field circuit thermal or electrical overload.
Frequently Asked Questions
Q: What are the total power thermal derating limits for the 1771-OAN at maximum ambient temperature?
A: At 30 deg C, the module supports 1.0 A per point, 2.0 A per group, and 8.0 A total module load. When ambient field temperatures reach 60 deg C, linear thermal derating reduces maximum current limits to 0.3 A per point, 0.6 A per group, and 2.4 A total module continuous current.
Q: Can the 1771-OAN module be key-indexed to prevent incorrect installation into a 1771 chassis slot?
A: Yes, plastic keying bands must be installed on the 1771 backplane connector between pins 10 and 12, and between pins 24 and 26. This hardware indexing prevents insertion of low-voltage DC or specialized analog modules into slots configured for high-voltage AC field connections.
Field Installation Guidelines
- Power Isolation: Ensure main backplane power and external 80-265 VAC field power sources are fully de-energized prior to inserting or removing the module from the 1771 chassis.
- Keying Band Verification: Verify chassis backplane slot keying positions (pins 10-12 and 24-26) to match the 1771-OAN card edge connector alignment before applying seating pressure.
- Wiring & Termination: Connect field wiring to the designated 1771 field wiring arm. Ensure solid-state AC return paths are correctly routed to their respective group commons (4 groups, 8 points per group).
- Current Limiting: Install external fast-acting fuses rated for individual branch circuit conductor protection based on ambient temperature loading profiles.
- Grounding & Shielding: Terminate line safety grounds directly to the chassis ground bus using standard industrial grounding practices to prevent ground loops and high-frequency noise injection.
Allen-Bradley 1771-OAN 1771 Digital AC Output Module
Allen-Bradley 1771-OAN 1771 Digital AC Output Module
Configured for high-density AC load switching in Allen-Bradley 1771 I/O chassis, the Allen-Bradley 1771-OAN, also cataloged as the 1771-OAN Digital Output Module, provides direct physical/electrical execution. It handles discrete control signal routing across 32 isolated AC solid-state output points. The module interfaces directly with standard field-side AC actuators, motor starters, solenoids, and indicators via the system backplane without requiring interposing relays.
Hardware Specifications
| Parameter | Specification |
|---|---|
| Model | 1771-OAN |
| Brand | Allen-Bradley |
| Origin | USA |
| Weight | 2.95 lbs (1.34 kg) |
| Dimensions | Standard 1771 Single-Slot I/O Module |
| Operating Temp | 0 to 60 deg C |
| Power Consumption | Backplane Current: 300 mA at 5 VDC |
| Output Points | 32 points (4 isolated groups of 8) |
| Voltage Range | 80 to 265 VAC |
| Nominal Voltage | 120 to 240 VAC |
| Output Current per Point | 1.0 A at 30 deg C / 0.3 A at 60 deg C |
| Output Current per Group | 2.0 A at 30 deg C / 0.6 A at 60 deg C |
| Output Current per Module | 8.0 A at 30 deg C / 2.4 A at 60 deg C |
Backplane Bus & Deterministic I/O Execution
The module interfaces with the Allen-Bradley PLC-5 system via the 1771 parallel backplane bus architecture. Deterministic I/O data processing is maintained by synchronized backplane scan cycles, transferring 32-bit output status words directly from the processor image table. Advanced optical isolation protects internal backplane logic components from field-side voltage transients up to 1500 VAC. Signal routing, output state latches, and power switching circuitry are partitioned across four independent electrical groups, mitigating total module loss in the event of localized field circuit thermal or electrical overload.
Frequently Asked Questions
Q: What are the total power thermal derating limits for the 1771-OAN at maximum ambient temperature?
A: At 30 deg C, the module supports 1.0 A per point, 2.0 A per group, and 8.0 A total module load. When ambient field temperatures reach 60 deg C, linear thermal derating reduces maximum current limits to 0.3 A per point, 0.6 A per group, and 2.4 A total module continuous current.
Q: Can the 1771-OAN module be key-indexed to prevent incorrect installation into a 1771 chassis slot?
A: Yes, plastic keying bands must be installed on the 1771 backplane connector between pins 10 and 12, and between pins 24 and 26. This hardware indexing prevents insertion of low-voltage DC or specialized analog modules into slots configured for high-voltage AC field connections.
Field Installation Guidelines
- Power Isolation: Ensure main backplane power and external 80-265 VAC field power sources are fully de-energized prior to inserting or removing the module from the 1771 chassis.
- Keying Band Verification: Verify chassis backplane slot keying positions (pins 10-12 and 24-26) to match the 1771-OAN card edge connector alignment before applying seating pressure.
- Wiring & Termination: Connect field wiring to the designated 1771 field wiring arm. Ensure solid-state AC return paths are correctly routed to their respective group commons (4 groups, 8 points per group).
- Current Limiting: Install external fast-acting fuses rated for individual branch circuit conductor protection based on ambient temperature loading profiles.
- Grounding & Shielding: Terminate line safety grounds directly to the chassis ground bus using standard industrial grounding practices to prevent ground loops and high-frequency noise injection.
