PRODUCT INFORMATION
Product Overview
The Allen-Bradley 1785-L40C is a PLC-5 Processor Module designed for 1771 I/O chassis systems. It installs directly into an I/O slot of a compatible 1771 chassis. The unit provides 48 kilowords of maximum user memory in battery-backed static RAM. It controls field inputs and outputs with a maximum capacity of 2048 I/O points. The program scan rate is 0.5 milliseconds per kiloword for bit logic. Typical scan time reaches 2 milliseconds per kiloword during general control operations.
This processor module features integrated ControlNet network communication with an RJ45 network access port. ControlNet transmission operates at 5 megabits per second with user-selectable network update times from 2 to 100 milliseconds. The module draws 3.3 amperes of backplane current at 5 volts DC. Operating thermal dissipation reaches a maximum of 59 BTU per hour. It supports hot backup architectures when paired with the 1785-CHBM ControlNet Hot Backup Cartridge.
TECHNICAL DATA
Technical Specifications
| Parameter | Specification |
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| Category | PLCs |
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| UPC | 612598139330 |
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| Weight | 4.19 lbs (1.90 kg) |
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| Module Type | ControlNet Processor Module |
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| Processor | PLC-5/40 |
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| Max User Memory Words | 48 Kilowords |
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| Battery-Backed Static RAM | Yes |
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| EEPROM Program Backup Option (using 1785-ME16, -ME32, -ME64, and -M100) | Yes |
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| Protected Memory | No |
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| Max Total I/O | 2048 (any mix) or 2048 in + 2048 out (complementary) |
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| Max Analog I/O | 2048 |
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| I/O Scan Time Per Rack | 10 ms at 57.6 kbits/s, 7 ms at 115.2 kbits/s, 3 ms at 230.4 mbits/s |
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| Max I/O Chassis Total | 61 |
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| Max I/O Chassis Extended Local | 0 |
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| Max I/O Chassis Universal Remote | 32 Max. Per I/O Link |
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| RS-232-C/422-A/423- A Ports | 1 |
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| Control Coprocessor Expansion Port | Yes |
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TECHNICAL INFORMATION
Features
- Provides 48 kilowords of battery-backed static RAM for user program storage.
- Supports up to 2048 total I/O in standard or complementary configurations.
- Integrated ControlNet port enables 5 megabits per second communication rates.
- Features user-selectable ControlNet update times between 2 and 100 milliseconds.
- Includes an auxiliary control coprocessor expansion port for expanded processing.
- Compatible with 1785-ME series EEPROM backup modules for non-volatile program retention.
TECHNICAL INFORMATION
Connections / Interfaces
- One base-configured ControlNet network access port with an RJ45 connector interface.
- One 25-pin D-shell serial port supporting RS-232-C, RS-422-A, and RS-423-A standards.
- One 8-pin mini-DIN connector dedicated to programming terminal connections.
- One 3-pin connector assigned for default Data Highway Plus communication links.
- One control coprocessor expansion port for dedicated coprocessor hardware.
TECHNICAL INFORMATION
Installation Guidelines
- Install the processor directly into the designated slot of the 1771 chassis.
- Verify that the backplane power supply can deliver at least 3.3 amperes at 5 volts DC.
- Maintain ambient operating temperatures between 0 and 60 degrees Celsius.
- Ensure noncondensing relative humidity stays within 5 to 95 percent during operation.
TECHNICAL INFORMATION
Compatibility
- Mounts into any standard Allen-Bradley 1771 I/O chassis.
- Interfaces with 1771, 1794, 1746, and 1791 8-point, 16-point, and 32-point I/O modules.
- Supports intelligent I/O modules across distributed network architectures.
- Pairs with the 1785-CHBM ControlNet Hot Backup Cartridge for redundant system setups.
- Accepts 1785-ME16, 1785-ME32, 1785-ME64, and 1785-M100 EEPROM program backup modules.
TECHNICAL INFORMATION
Compliance and Certifications
- UL certified.
- CSA certified.
- CE marked.
- C-Tick compliant.
COMPATIBILITY
Compatibility & Replacement
COMPATIBLE MODELSMounts into any standard Allen-Bradley 1771 I/O chassis. Interfaces with 1771, 1794, 1746, and 1791 8-point, 16-point, and 32-point I/O modules. Supports intelligent I/O modules across distributed network architectures. Pairs with the 1785-CHBM ControlNet Hot Backup Cartridge for redundant system setups. Accepts 1785-ME16, 1785-ME32, 1785-ME64, and 1785-M100 EEPROM program backup modules.
Verify compatibility against the exact Part Number, revision and manufacturer documentation before ordering.
PART VERIFICATION
Before You Order
Industrial automation parts can share similar model names, suffixes and revisions. Confirm the complete manufacturer Part Number before purchase.
01Check Part NumberMatch the complete ordering code on the existing unit.
02Confirm RevisionCheck suffix, hardware or firmware when applicable.
03Send a Label PhotoWe can review a clear label photo when identification is uncertain.
ORDERING PROCESS
From RFQ to Dispatch
1Submit Part Number2Verify Product Identity3Confirm Stock & Condition4Issue Quotation5Dispatch & Tracking
PRODUCT FAQ
Frequently Asked Questions
What is the maximum user memory capacity of the 1785-L40C?
The 1785-L40C processor module provides 48 kilowords of maximum user memory in battery-backed static RAM.
Which communication ports are available on the 1785-L40C module?
The module includes an RJ45 ControlNet port, an 8-pin mini-DIN programming port, and a DH+ port. It also provides a 25-pin serial port and a coprocessor expansion interface.
What backplane power is required by the 1785-L40C processor?
The unit requires 3.3 amperes of backplane current at 5 volts DC during standard operation.
What is the indicative reference pricing for the 1785-L40C processor module?
Published figures represent indicative market reference pricing only and are not a final quotation. Actual costs depend on condition, stock levels, quantity, and delivery requirements.
