PRODUCT INFORMATION
Product Overview
The Allen-Bradley 1771-A1B is a 4-slot I/O Chassis for the PLC-5 system. This unit provides the communication path between installed I/O modules and the controller or adapter module. It acts as an enclosure for processors, power supply modules, remote I/O adapters, and extended-local I/O adapters. The far-left slot is reserved specifically for the processor module or adapter module. Other chassis slots accept compatible communication modules, I/O modules, or power supply modules.
The 1771-A1B chassis is designed for back-panel mounting inside an open-style industrial enclosure. It supports a maximum backplane current capacity of 16 amperes operating at 5 volts DC. Chassis power can originate from integral processor supplies, chassis-mounted power modules, or external power supplies. An integrated configuration jumper sets power delivery between external supply mode and module supply mode. Simultaneous operation of both a power supply module and an external power supply is prohibited. Grounding studs located on the metal chassis connect directly to the central ground bus.
TECHNICAL DATA
Technical Specifications
| Parameter | Specification |
|---|
| Category | PLCs |
|---|
| Weight | 5.94 lbs (2.69 kg) |
|---|
| Module Type | I/O Chasis |
|---|
| Number of Module I/O Slots | 4 Slots |
|---|
| Max Backplane Current (at 5 Volts DC) | 16 Amperes |
|---|
| Mount Type | Back Panel |
|---|
| Enclosure Type | Open Style |
|---|
| Operating Shock | 15 g |
|---|
| Nonoperating Shock | 30 g |
|---|
| Vibration | 2 g (at 10-500 Hertz) |
|---|
| Location | Stand-Alone |
|---|
TECHNICAL INFORMATION
Features
- Accommodates four standard 1771 I/O modules, power supplies, or controllers.
- Allocates the far-left slot strictly for the main controller or adapter module.
- Supports up to 16 amperes of maximum backplane current at 5 volts DC.
- Features a dedicated power selection jumper with 'N' and 'Y' position settings.
- Allows side-plate mounting for 1771-P1, 1771-P2, 1771-P7, and 1771-PS7 external power supplies.
- Includes chassis grounding studs for direct connection to central plant ground.
TECHNICAL INFORMATION
Applications
- Houses Allen-Bradley PLC-5 processors and remote I/O adapters in automation enclosures.
- Provides local backplane signal distribution for 1771 digital and analog I/O assemblies.
TECHNICAL INFORMATION
Connections / Interfaces
- Backplane connectors interface four 1771 series modules directly to the system bus.
- Dedicated chassis grounding studs provide physical bonding to the main control ground bus.
TECHNICAL INFORMATION
Installation Guidelines
- Mount the chassis securely onto a back panel inside a protective industrial enclosure.
- Connect the grounding studs on the chassis directly to a central ground bus.
- Verify that the power configuration jumper matches the chosen power supply architecture.
- Place the system processor or remote I/O adapter into the dedicated far-left slot.
TECHNICAL INFORMATION
Configuration Guidelines
- Set the power supply jumper to 'N' when utilizing an external power source.
- Set the jumper to 'Y' when using a power supply module or integral processor power.
- Do not connect a power supply module and an external power supply simultaneously.
TECHNICAL INFORMATION
Compatibility
- Compatible with Allen-Bradley PLC-5 processors featuring integral power supplies producing 2 to 4 amps.
- Supports 1771 power supply modules providing between 3 and 8 amps.
- Accepts external power supplies delivering between 6.5 and 16 amps.
- Mounts 1771-P1, 1771-P2, 1771-P7, and 1771-PS7 supplies on the left side plate.
COMPATIBILITY
Compatibility & Replacement
COMPATIBLE MODELSCompatible with Allen-Bradley PLC-5 processors featuring integral power supplies producing 2 to 4 amps. Supports 1771 power supply modules providing between 3 and 8 amps. Accepts external power supplies delivering between 6.5 and 16 amps. Mounts 1771-P1, 1771-P2, 1771-P7, and 1771-PS7 supplies on the left side plate.
Verify compatibility against the exact Part Number, revision and manufacturer documentation before ordering.
PART VERIFICATION
Before You Order
Industrial automation parts can share similar model names, suffixes and revisions. Confirm the complete manufacturer Part Number before purchase.
01Check Part NumberMatch the complete ordering code on the existing unit.
02Confirm RevisionCheck suffix, hardware or firmware when applicable.
03Send a Label PhotoWe can review a clear label photo when identification is uncertain.
ORDERING PROCESS
From RFQ to Dispatch
1Submit Part Number2Verify Product Identity3Confirm Stock & Condition4Issue Quotation5Dispatch & Tracking
PRODUCT FAQ
Frequently Asked Questions
How many module slots does the Allen-Bradley 1771-A1B chassis provide?
The 1771-A1B chassis provides four slots for mounting PLC-5 controllers, adapters, and 1771 I/O modules.
Which slot must house the PLC-5 processor or adapter module?
The far-left slot in the 1771-A1B chassis is reserved for the processor or adapter module.
How is the power supply configuration jumper set on the 1771-A1B?
Position 'N' selects external power. Position 'Y' selects a power supply module or integral processor power.
Can an external power supply and a power supply module run together?
No. The 1771-A1B chassis cannot receive power from both an external supply and a module simultaneously.
