OVERVIEW

Official designation: Allen-Bradley 2755-DD4A (Bulletin 2755, Dual-Head Barcode Decoder)

Role/Application: This dual-head barcode decoder processes data simultaneously from two connected scanners, providing flexible coordination and communication to a host device via RS-232/TTL interfaces for industrial automation applications.

KEY SPECS SUMMARY

Power: 100 to 240 Volts AC

Interfaces / Ports: 2 Scanner ports, AUX, HOST ports

Indicators: 17 status LEDs

Operating Temp: Refer to the latest manufacturer manual.

Platform / Compatibility: Compatible with Allen-Bradley 2755 scanners

Limit: Maximum 2 scanners

Lifecycle: Discontinued by manufacturer, varies by revision

FREQUENTLY ASKED QUESTIONS

Technical Specifications:

Q: What are the primary communication protocol options supported by the HOST port on the 2755-DD4A?

A: The HOST port supports RS-232, RS-422, and RS-485 with the DH485 protocol.

Wiring & Installation:

Q: Is external power required for the scanners connected to Scanner Port A and Scanner Port B?

A: No, the connected scanners are powered directly by the decoder and do not require separate power.

Troubleshooting & Compatibility:

Q: Does the decoder retain its configuration settings if power is temporarily interrupted or lost?

A: Configuration is retained for up to 6 hours at 50 degrees C via an onboard capacitor, or longer with an optional battery.

Replacement & Upgrades:

Q: Can an optional I/O module be added to the 2755-DD4A for discrete control outputs?

A: Yes, an optional I/O module board can be ordered to enable up to 8 discrete outputs.