Description

Allen-Bradley 1769-ASCII CompactLogix ASCII Communication Module

The Allen-Bradley 1769-ASCII, also cataloged as the 1769-ASCII ASCII Communication Module, operates as a dedicated hardware component for ASCII data exchange within CompactLogix and MicroLogix 1500 controller platforms. The module provides two configurable serial ports for RS-232, RS-422, and RS-485 communication.

Hardware Specifications

Parameter	Specification
Model	1769-ASCII
Brand	Allen-Bradley
Origin	United States
Product Type	Specialty Communication Module
Product Line	CompactLogix
Module Type	ASCII Communication Interface Module
Weight	0.13 lbs (0.06 kg)
Dimensions	Not specified by manufacturer
Operating Temp	0 to 62 deg C (32 to 140 deg F)
Power Consumption	33.6 Watts
Mounting	DIN Rail or Panel Mount Chassis Installation
Series	A and B
Communication Ports	Two serial ports
Serial Interfaces	RS-232, RS-422, RS-485
Port Configuration	Individually configured ASCII communication channels
Handshaking	RTS/CTS hardware handshaking enabled
Input Words	108
Configuration Words	31
Isolation Voltage	30 Volts continuous
Power Rating	425 mA at 5 VDC
Backplane Current	1.4 A at 24 V
Power Dissipation, Max	2.13 Watts
Thermal Dissipation	7.3 BTU/hr
Serial Input Voltage Signal	3 to 25 VDC for active low state; -3 to -25 VDC for inactive high state
Recommended Cable	Belden 8761 shielded cable
Serial Port Status Monitoring	TX FIFO overflow, RX FIFO overflow, RX parity error, handshake error, new data flag
Transaction ID Range	0 to 255
UNSPSC	32151705

EtherNet/IP and CompactLogix Backplane Integration

The 1769-ASCII module operates as a CompactLogix expansion component through the 1769 backplane interface. Therefore, the controller exchanges configuration, status, and ASCII data through the local I/O architecture. The module supports I/O density scaling by adding dedicated serial communication channels without occupying controller communication ports.

Furthermore, the module maintains compatibility with CompactLogix and MicroLogix 1500 controllers. The system configuration defines communication parameters, message handling, and serial transaction processing through the controller programming environment.

Frequently Asked Questions

Q: How many serial communication channels does the 1769-ASCII provide?
A: The module provides two independent serial ports. Each port can be configured separately for ASCII communication using RS-232, RS-422, or RS-485 electrical interfaces.

Q: Does the module support hardware handshaking?
A: Yes. The 1769-ASCII supports RTS/CTS hardware handshaking for serial communication control.

Q: What cable type does the manufacturer recommend for installation?
A: The recommended cable type is Belden 8761 shielded cable. The shield should follow standard industrial grounding practices to reduce electrical noise coupling.

Field Installation Guidelines

Install the 1769-ASCII module on the CompactLogix 1769 chassis according to the controller system layout requirements. Verify that the module remains within the rated power supply distance specification before completing the installation.

Use shielded serial cables for all field connections. Route communication wiring separately from high-voltage power conductors and motor cables to reduce electromagnetic interference.

Connect the cable shield according to the plant grounding standard. Avoid creating unnecessary ground loops while maintaining effective noise suppression.

Before commissioning, verify RS-232, RS-422, or RS-485 wiring polarity, communication parameters, and controller configuration settings. Confirm TX and RX status indicators during initial communication testing.

Specifications

• Brand: Allen Bradley

Advantages

• High reliability in industrial environments
• Supports continuous operation
• Compatible with major PLC/DCS systems