Product Overview – 1771-IN Digital AC/DC Input Module
The 1771-IN is a PLC 5 series digital input module from Allen-Bradley. It occupies just 1 slot in a 1771 chassis. This module provides 8 input channels for 24V AC/DC signals. It converts field signals to logic levels for the processor. It works with pushbuttons, limit switches, and pilot lights.
Key Technical Data
- Manufacturer: Rockwell Automation / Allen-Bradley
- Part Number: 1771-IN
- Inputs: 8 (AC/DC)
- Voltage Category: 24V AC/DC (AC operating: 12-28V)
- Backplane Current: 80 mA
- Max AC Off-State Current: 2.8 mA
- Signal Delay (AC On/Off): 18 ms ±10 ms
- Power Dissipation: 0.4 W (min) – 5.4 W (max)
- Wiring Arm: 1771-WA (included)
- Mounting: Rack mountable
Installation & Integration
- Fits any Allen-Bradley Bulletin 1771 I/O chassis.
- Uses 1771-WA wiring arm – no need to disconnect wires for replacement.
- Optoelectrical isolation and filter circuits simplify troubleshooting.
- Front-panel status LEDs show each input’s ON/OFF condition.
- Fault mode selection via configuration plug on PCB – choose last state or reset.
Typical Applications & Compatible Devices
- Pushbuttons and selector switches
- Limit switches and proximity sensors
- Pilot lights and annunciators
- Motor starter auxiliary contacts
- Compatible with all current Allen-Bradley programmable controllers
Oiltech Controls’s Insight
- This module is ideal for systems where 24V AC/DC signals are common.
- Its low power dissipation (5.4W max) reduces heat load in the cabinet.
- The fault mode selection is a key feature for critical output states.
- We recommend verifying your chassis backplane current capacity before installation.
- For obsolete systems, this module is a reliable drop-in replacement.
Professional FAQ – 5 Expert Questions
- Q: Can I use this module with a 24V DC sensor?
A: Yes, it accepts 24V AC/DC. However, the operating voltage is specified for AC (12-28V); for DC, verify your sensor’s output matches the module’s input range. - Q: How do I set the fault mode (last state vs. reset)?
A: Use the configuration plug on the edge of the PCB. Refer to the manual for exact jumper settings. We recommend testing the selected mode during commissioning. - Q: What is the maximum off-state current, and why does it matter?
A: Max AC off-state current is 2.8 mA. This ensures the module does not falsely detect an ON state due to leakage current from sensors or wiring. - Q: Is the 1771-WA wiring arm necessary?
A: It is highly recommended. It allows you to remove the module without disconnecting field wiring, saving time during maintenance. - Q: How do I know if my chassis power supply can handle this module?
A: The module draws 80 mA from the backplane. Add up all module currents in your chassis and compare to your power supply’s rating. We can help you calculate this.
Why Buy From Oiltech Controls?
- Over 15 years of experience in industrial automation spare parts.
- We ship globally with FedEx, UPS, or DHL – 24 to 28 hours dispatch.
- All units are tested before shipment – we verify functionality.
- We offer tested surplus and refurbished options with full warranty.
- 12-month warranty on every product.
- Technical verification before shipping – we check every detail.
- Expert support for obsolete control systems.
Contact:
info@oiltechcontrols.com |
+86 158 8020 0923 (WhatsApp)
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