Allen-Bradley 1785-MJ PLC Memory Module
The 1785-MJ is an Allen-Bradley EEPROM memory module with an 8K-word memory capacity, specified for use with PLC-5/15, PLC-5/25, and PLC-2/17 programmable logic controllers. It provides non-volatile memory storage for controller program data, making it a replacement memory component for supported legacy PLC systems. The manufacturer has discontinued this module.
Memory Configuration
The 1785-MJ uses EEPROM (Electrically Erasable Programmable Read-Only Memory) technology. Unlike volatile memory, EEPROM retains stored data without continuous power, allowing the stored program information to remain available when the controller is powered down.
Its 8K memory capacity is intended for the specified PLC processor configurations. The supplied information does not identify the memory word width or detailed programming and retention specifications.
Processor Compatibility
The supplied product description identifies the following compatible controller models:
- Allen-Bradley PLC-5/15
- Allen-Bradley PLC-5/25
- Allen-Bradley PLC-2/17
These processor designations are important when selecting a replacement module. Compatibility should be checked against the installed controller and its existing memory configuration rather than assumed across the entire PLC-5 or PLC-2 product families.
Technical Specifications
| Parameter | Specification |
|---|---|
| Model | 1785-MJ |
| Brand | Allen-Bradley |
| Product Type | PLC Memory Module |
| Memory Capacity | 8K |
| Memory Technology | EEPROM |
| Compatible Processors | PLC-5/15, PLC-5/25, PLC-2/17 |
| Weight | 0.05 lbs |
| Manufacturer Status | Discontinued |
Product Status and Warranty
The Allen-Bradley 1785-MJ is discontinued by the manufacturer. The supplied product listing states that the original factory warranty does not apply and includes a Radwell 2-year warranty.
For replacement applications, verify the existing memory module designation and controller model before ordering. The EEPROM memory technology distinguishes this module from memory modules using other storage technologies.
Frequently Asked Questions
Q: Which PLC processors are compatible with the 1785-MJ?
A: The supplied specifications list PLC-5/15, PLC-5/25, and PLC-2/17 processors. Compatibility with other processor models is not established by the available information.
Q: What is the difference between EEPROM and CMOS memory?
A: EEPROM is non-volatile memory that retains stored information without continuous power. CMOS alone does not establish non-volatile data retention, so the 1785-MJ should not be treated as interchangeable with a CMOS memory module solely because both have an 8K capacity.
Q: Is the Allen-Bradley 1785-MJ still manufactured?
A: No. The manufacturer has discontinued the 1785-MJ. The supplied listing specifies a Radwell 2-year warranty rather than the original factory warranty.
Allen-Bradley 1785-MJ PLC Memory Module
Allen-Bradley 1785-MJ PLC Memory Module
The 1785-MJ is an Allen-Bradley EEPROM memory module with an 8K-word memory capacity, specified for use with PLC-5/15, PLC-5/25, and PLC-2/17 programmable logic controllers. It provides non-volatile memory storage for controller program data, making it a replacement memory component for supported legacy PLC systems. The manufacturer has discontinued this module.
Memory Configuration
The 1785-MJ uses EEPROM (Electrically Erasable Programmable Read-Only Memory) technology. Unlike volatile memory, EEPROM retains stored data without continuous power, allowing the stored program information to remain available when the controller is powered down.
Its 8K memory capacity is intended for the specified PLC processor configurations. The supplied information does not identify the memory word width or detailed programming and retention specifications.
Processor Compatibility
The supplied product description identifies the following compatible controller models:
- Allen-Bradley PLC-5/15
- Allen-Bradley PLC-5/25
- Allen-Bradley PLC-2/17
These processor designations are important when selecting a replacement module. Compatibility should be checked against the installed controller and its existing memory configuration rather than assumed across the entire PLC-5 or PLC-2 product families.
Technical Specifications
| Parameter | Specification |
|---|---|
| Model | 1785-MJ |
| Brand | Allen-Bradley |
| Product Type | PLC Memory Module |
| Memory Capacity | 8K |
| Memory Technology | EEPROM |
| Compatible Processors | PLC-5/15, PLC-5/25, PLC-2/17 |
| Weight | 0.05 lbs |
| Manufacturer Status | Discontinued |
Product Status and Warranty
The Allen-Bradley 1785-MJ is discontinued by the manufacturer. The supplied product listing states that the original factory warranty does not apply and includes a Radwell 2-year warranty.
For replacement applications, verify the existing memory module designation and controller model before ordering. The EEPROM memory technology distinguishes this module from memory modules using other storage technologies.
Frequently Asked Questions
Q: Which PLC processors are compatible with the 1785-MJ?
A: The supplied specifications list PLC-5/15, PLC-5/25, and PLC-2/17 processors. Compatibility with other processor models is not established by the available information.
Q: What is the difference between EEPROM and CMOS memory?
A: EEPROM is non-volatile memory that retains stored information without continuous power. CMOS alone does not establish non-volatile data retention, so the 1785-MJ should not be treated as interchangeable with a CMOS memory module solely because both have an 8K capacity.
Q: Is the Allen-Bradley 1785-MJ still manufactured?
A: No. The manufacturer has discontinued the 1785-MJ. The supplied listing specifies a Radwell 2-year warranty rather than the original factory warranty.
