Configured for memory storage within PLC-3 control hardware, the Allen-Bradley 1775-MEA (1775MEA Memory Module) provides RAM-based data storage through the PLC backplane interface. The supplied data identifies it as an error-correcting RAM module with 5 VDC backplane power.

Model Identification

The supplied information identifies 1775-MEA as a PLC-3 memory module. No validated suffix breakdown is provided, so the catalog designation is retained without assigning functional meaning to individual characters.

Hardware Specifications

PLC-3 Memory Interface Characteristics

The 1775-MEA receives 5 VDC power through the PLC backplane and operates as a memory component within the PLC-3 hardware architecture. The supplied specification identifies 1.5 W typical power consumption and 35 uA battery current in backup mode.

The supplied product description states 64K error-correcting RAM, while the detailed specification states 4K Words (8 KB). These values are inconsistent because 64K capacity and 4K Words represent different memory sizes. The exact installed capacity should therefore be confirmed from the physical module marking or applicable Allen-Bradley documentation before procurement or replacement.

Ordering Information

• 1 x Allen-Bradley 1775-MEA memory module
• 1 x Memory module hardware
• No additional mounting kit, programming device, or external accessory is identified in the supplied data

Installation and Handling

Backplane Installation

• Install the module only in a compatible PLC-3 hardware configuration.
• Confirm the backplane connector is clean and free of conductive contamination before insertion.
• Remove power before installing or removing the module unless the applicable PLC-3 documentation explicitly permits energized replacement.
• Do not force the module into the backplane connector.
• Verify that the module is mechanically seated before restoring system power.

Electrical Practices

• Confirm the backplane supply provides the specified 5 VDC +/-5%.
• Keep memory module wiring and adjacent conductors free from unnecessary electromagnetic interference sources.
• Maintain proper cabinet grounding and bonding according to the control system installation requirements.
• Avoid handling connector contacts directly to reduce contamination and electrostatic discharge risk.
• Observe ESD precautions when handling the memory module outside its installed position.

Frequently Asked Questions

• What controller family is the 1775-MEA associated with?

  The supplied data identifies the 1775-MEA as a memory module for the Allen-Bradley PLC-3 platform.

• What backplane voltage does the module require?

  The specified requirement is 5 VDC +/-5%, supplied through the PLC backplane.

• What is the typical power consumption?

  The supplied specification lists 1.5 W typical power consumption during normal operation.

• What is the battery current specification?

  Battery current is specified as 35 uA in backup mode. No additional battery characteristics are provided in the supplied data.

• What temperature range is specified for operation?

  The stated operating temperature range is 0 deg C to +60 deg C. Storage is specified separately from -40 deg C to +85 deg C.

• Does the supplied data confirm the exact memory capacity?

  No. It lists both 64K error-correcting RAM and 4K Words (8 KB). The physical module marking or original documentation should resolve this conflict.

• Is hot-swapping supported?

  Hot-swapping is not confirmed by the supplied information. Treat the module as a power-off installation unless the applicable PLC-3 documentation explicitly permits energized replacement.

• What environmental humidity is specified?

  The specified humidity range is 5-95% RH, non-condensing. Installation should prevent condensation inside the control enclosure.