1769-L27ERM-QBFC1B: Installation, Studio 5000 Configuration, and First Program Guide
The 1769-L27ERM-QBFC1B is a CompactLogix 5370 L2 controller with 1 MB of user memory, a dual-port EtherNet/IP interface, and support for up to 4 local 1769 Compact I/O modules connected directly to the right side of the packaged controller. It is a packaged controller: the controller, an embedded 24V DC power supply, and embedded I/O (16 DC inputs, 16 DC outputs, 4 high-speed counters, 4 universal analog inputs, and 2 analog outputs) are built into one unit. The CompactLogix 5370 platform is widely deployed in standalone machine control, small process skids, and OEM equipment. This guide covers system assembly, power wiring, Studio 5000 project creation, EtherNet/IP network setup, program download, and LED troubleshooting.
Contents
1. Controller Overview
The 1769-L27ERM-QBFC1B is a packaged programmable automation controller in the CompactLogix 5370 family. The controller integrates an embedded 24V DC power supply and embedded I/O (16 DC inputs, 16 DC outputs, 4 high-speed counters with 4 counter outputs, 4 universal analog inputs, 2 analog outputs), plus a 1769 CompactBus for up to 4 Compact I/O expansion modules. It is designed for standalone machine control and small distributed systems requiring dual-port EtherNet/IP connectivity and local 1769 Compact I/O expansion. The controller is programmed with Studio 5000 Logix Designer and supports Relay Ladder Logic, Structured Text, Function Block Diagram, and Sequential Function Chart languages.
Catalog Number Breakdown
| Code | Meaning | Value |
|---|---|---|
| 1769 | Platform | CompactLogix 1769 |
| L27 | Controller class and memory | L2 class, 1 MB user memory |
| ERM | Communication / motion | Dual-port embedded EtherNet/IP (DLR capable) with Integrated Motion on EtherNet/IP (up to 4 axes) |
| QBFC1B | Embedded I/O | 16 DC inputs, 16 DC outputs, 4 high-speed counters, 4 universal analog inputs, 2 analog outputs; embedded 24V DC power supply |
Key Specifications
| Parameter | Value |
|---|---|
| Standard Memory | 1 MB |
| Local 1769 I/O Modules | Up to 4, connected directly to the right side of the controller |
| Embedded I/O | 16 DC digital inputs, 16 DC digital outputs, 4 high-speed counters (4 counter outputs), 4 universal analog inputs, 2 analog outputs |
| Local I/O Banks | 1 (additional I/O via EtherNet/IP remote I/O adapters) |
| Controller Tasks | 32 (only one can be continuous; the rest periodic or event) |
| EtherNet/IP Nodes, max | 16 |
| Integrated Motion on EtherNet/IP | Up to 4 axes |
| Built-in Communication | Dual-port EtherNet/IP (10/100 Mbps), embedded; USB 2.0 full-speed (12 Mbps) |
| EtherNet/IP Topology | Star, linear, Device Level Ring (DLR) |
| USB | USB 2.0 full speed (12 Mbps) — for temporary local programming only |
| Power Supply | Embedded 24V DC input, isolated (supplied from an external 24V DC source) |
| Current Draw @ 5V DC (controller power) | 1 A |
| Current Draw @ 24V DC (controller power) | 0.8 A |
| Power Dissipation, max | 21 W |
| Operating Temperature | 0…60°C (32…140°F) |
| Nonvolatile Memory | 1784-SD1 SD card (1 GB, shipped with the controller); 1784-SD2 (2 GB) available separately |
| Weight | Approx. 0.9 kg (1.9 lb) |
| Module Width | 140 mm (5.51 in.) |
| Enclosure | None (open style) |
| Module Location | 35 mm DIN rail or panel mount |
| Temperature Code | T3C (North America); T4 (IECEx) |
| Programming Languages | Relay ladder logic (RLL), Structured text, Function block diagram, Sequential function chart (SFC) |
CompactLogix 5370 vs 5380
The 1769-L27ERM is a CompactLogix 5370 controller (previous generation). The current generation is the CompactLogix 5380 (5069-L306ER and similar). Key differences: the 5370 uses 1769 Compact I/O (tongue-and-groove bus), while the 5380 uses 5069 Compact 5000 I/O (high-speed local bus). The 5370 connects I/O modules directly to the right side of the controller. Both are programmed with Studio 5000 Logix Designer.
2. Hardware Installation
The 1769-L27ERM-QBFC1B is a packaged controller with an embedded 24V DC power supply and embedded I/O. Local 1769 Compact I/O modules mount directly to the right side and connect via the 1769 tongue-and-groove expansion bus.
System Assembly
The 1769-L27ERM supports up to 4 local 1769 I/O modules connected directly to the right side of the controller. A right end cap (1769-ECR) must be installed on the last module to terminate the expansion bus.
| Position | Component | Notes |
|---|---|---|
| Position 1 (leftmost) | Controller (1769-L27ERM-QBFC1B) | Includes embedded 24V DC power supply |
| Embedded I/O | Two embedded I/O modules on the controller | Shown as slots [1], [2] and [3] in the Controller Organizer (the second embedded module appears as two modules) |
| Positions 2–5 | Up to 4 local 1769 I/O modules | Examples: 1769-IQ16, 1769-OB16, 1769-IF4, 1769-OF2 |
| Right end | 1769-ECR right end cap | Required to terminate the expansion bus |
Installation Steps
- Mount the controller on a 35 mm DIN rail or panel-mount using two screws. Allow 50 mm (2 in.) of clearance from enclosure walls, wireways, and adjacent equipment on all sides.
- Connect each 1769 I/O module to the right side of the controller by aligning the tongue-and-groove bus connector and sliding the module until it locks into place.
- Install the 1769-ECR right end cap on the last I/O module to terminate the expansion bus. The end cap is mandatory — do not omit it.
- Wire 24V DC power from an external 24V DC power supply (Rockwell's example is a 1606 switched-mode supply): 24V DC+ to the controller's +24V DC terminal and 24V DC− to the COM terminal. Strip 8 mm (0.31 in.) of insulation. Leave the external supply off until all wiring is complete. If a switch or relay controls controller power, install it at the +24V DC terminal, not at COM.
- Connect the EtherNet/IP cable(s) to one or both of the dual Ethernet ports on the front of the controller.
- Install the 1784-SD1 SD card (shipped with the controller) if it is not already seated; it is used for program backup and restore. The SD card slot is located on the front of the controller.
- Wire field I/O devices (sensors, actuators) to the 1769 I/O module terminals per the module's wiring diagram.
End Cap Required
Every 1769 system must have a 1769-ECR (right) end cap installed on the last module. Without the end cap, the expansion bus is not properly terminated and communication faults will occur. A 1769-ECR end cap ships in the box with the controller.
24V DC Power Wiring
The 1769-L27ERM-QBFC1B has an embedded 24V DC input, isolated power supply. Do not connect AC line voltage to the controller. Power it from an external 24V DC power supply wired to the +24V DC and COM terminals, and disconnect all power before wiring. Confirm the external supply is certified for your application (for example, hazardous locations) before installing it.
3. Studio 5000 Project Setup
After installing the controller, create a Studio 5000 Logix Designer project to program and configure it.
Creating a New Project
- Open Studio 5000 Logix Designer.
- Select File → New Project.
- In the Controller list, expand CompactLogix 5370 and select 1769-L27ERM.
- Enter a Name for the controller (e.g., MachineLine1).
- Click OK. The project opens with the controller in the I/O Configuration tree.
Adding Local I/O Modules
- In the Controller Organizer, expand I/O Configuration → expand the CompactBus node (represents the local 1769 expansion bus).
- Right-click the CompactBus node → New Module.
- Search for the I/O module catalog number (e.g., 1769-IQ16 for a 16-point 24V DC input module), select it, and click Create.
- Set the Name and Slot number. The embedded I/O occupies slots 1 to 3 in the I/O tree, so the first expansion module to the right of the controller is slot 4.
- Click OK. Repeat for each local I/O module in the system.
1769 vs 5069 I/O
The CompactLogix 5370 only supports 1769 Compact I/O modules on its local expansion bus. It does not support 5069 Compact 5000 I/O modules locally. However, it can connect to 5069 remote I/O nodes via an EtherNet/IP adapter (5069-AENTR) on the EtherNet/IP network.
4. EtherNet/IP Network Configuration
The 1769-L27ERM has two embedded EtherNet/IP ports that support star, linear, and Device Level Ring (DLR) topologies. Both ports share a single IP address. For DLR, connect one port to each segment of the ring.
Setting the Controller IP Address
- Connect an Ethernet cable from one of the controller's dual Ethernet ports to your network switch or directly to your PC.
- Use the BOOTP/DHCP Server utility (included with Studio 5000) to assign a static IP address to the controller's MAC address.
- Alternatively, browse to the controller in RSLinx Classic via the EtherNet/IP driver and right-click to set the IP address.
- To assign the IP within Studio 5000, open the controller properties → General tab and enter the desired IP address, subnet mask, and gateway.
- For DLR ring topology, connect Port 1 to one node in the ring and Port 2 to the adjacent node. One device in the ring must be configured as the Ring Supervisor.
Adding Remote I/O Adapters
- In the I/O Configuration, right-click the Ethernet port node → New Module.
- Search for the remote adapter catalog number: 1734-AENT for POINT I/O, 5069-AENTR for Compact 5000 remote I/O, or 1769-AENTR for 1769 remote I/O.
- Set the IP Address, Name, and connection parameters to match the physical adapter.
- Right-click the adapter node → New Module to add remote I/O modules under the adapter. Repeat for each remote node.
5. Download & Go Online
After configuring the project, download it to the controller and go online to monitor execution.
Download Steps
- Set the controller keyswitch to REM (Remote) position.
- In Studio 5000, select Communications → Who Active (or click the communications path dropdown).
- Browse the network tree and select your 1769-L27ERM controller.
- Click Download. Studio 5000 transfers the project to the controller.
- When prompted, choose to go to Run Mode or Remote Program Mode.
- To go online without downloading, select Communications → Go Online.
Controller Operation Modes
| Mode | Description |
|---|---|
| Run | Controller executes the application program, scans I/O, and updates outputs. |
| Program | Controller does not execute logic. Outputs go to their configured fault state. Used for downloading and editing. |
| Remote Run | Same as Run, but mode can be changed remotely from Studio 5000. |
| Remote Program | Same as Program, but remotely changeable from Studio 5000. |
| Remote Test | Controller executes tasks with outputs disabled. Selectable from Studio 5000 only with the mode switch in REM. |
Mode Switch Positions
The physical keyswitch has three positions: RUN (forces Run mode), PROG (forces Program mode), and REM (allows mode changes from Studio 5000). For normal operation, leave the key in REM and control the mode from software.
6. Troubleshooting
The 1769-L27ERM-QBFC1B has several LED indicators on the front panel for diagnosing controller and network status. Refer to 1769-UM021 for the complete fault code listing.
LED Indicators
| LED | Color / State | Meaning |
|---|---|---|
| RUN | Green | Controller is in Run mode |
| RUN | Off | Controller is in Program or Test mode |
| FORCE | Yellow | I/O forces are active (enabled) -- review and remove forces |
| FORCE | Flashing yellow | Addresses have been forced, but the forces are not enabled |
| FORCE | Off | No tags contain I/O force values (normal) |
| I/O | Green | Controller is communicating with all devices in its I/O configuration |
| I/O | Flashing green | One or more devices in the I/O configuration are not responding |
| I/O | Flashing red | Controller is not communicating with any devices, or a controller fault has occurred |
| I/O | Off | Controller does not contain a project |
| OK | Green | Controller is OK |
| OK | Flashing green | Controller is storing a project to or loading a project from the SD card |
| OK | Red | Nonrecoverable major fault; the project was cleared from memory |
| OK | Flashing red | Firmware update required, major recoverable fault, nonrecoverable major fault that cleared the program, or firmware update in progress |
| OK | Off | No power is applied |
| NS | Green | Port has an IP address and CIP connections are established |
| NS | Flashing green | Port has an IP address, but no CIP connections are established |
| NS | Red | The assigned IP address is already in use |
| NS | Off | Port has no IP address and is operating in BOOTP or DHCP mode |
| LINK 1 / LINK 2 | Green | Link present on that port, no activity |
| LINK 1 / LINK 2 | Flashing green | Link present on that port with activity |
| LINK 1 / LINK 2 | Off | No link, port disabled, or (LINK 2) port disabled after a rapid ring fault |
| SD | Flashing green | Controller is reading from or writing to the SD card |
| SD | Flashing red | SD card does not have a file system |
| SD | Off | No SD card activity (normal) |
Common Issues
| Symptom | Likely Cause | Resolution |
|---|---|---|
| OK LED red flashing | Major recoverable fault, or firmware update required or in progress | Go online in Studio 5000 → Controller Properties → view the fault log. Correct the cause and clear the fault. If no firmware is loaded or an update is required, flash the controller firmware. |
| OK LED red steady | Nonrecoverable major fault; project cleared from memory | Note any fault codes, then cycle power and reload the project (from the SD card or by download). If the fault persists, the controller may require replacement. |
| OK LED off | No power to controller | Verify the external 24V DC supply is on and that 24V DC is present at the controller's +24V DC and COM terminals. |
| Cannot go online | Communication path not configured | Verify Ethernet cable, confirm IP address, and ensure the RSLinx EtherNet/IP driver is configured. Try the USB port as a fallback for local programming. |
| Controller in Program mode, won't switch to Run | Keyswitch in PROG position | Turn the key to REM, then change mode from Studio 5000. |
| I/O module shows yellow triangle in Controller Organizer | Module configuration mismatch or missing end cap | Verify module catalog number, slot number, and electronic keying settings. Confirm the 1769-ECR end cap is installed on the last module. Re-download the project. |
| LINK LEDs off | No Ethernet link on that port | Check cable connection at the controller port and switch. Try a known-good cable. Verify the switch port is active. |
USB Port
The USB port is intended for temporary local programming only. Do not exceed a 3.0 m (9.8 ft) cable length. Do not use the USB port in hazardous locations. The USB port does not support EtherNet/IP connections or remote I/O communication.
7. Related CompactLogix 5370 Controllers
| Cat. No. | Memory | Max Local Modules | Ethernet Ports | Notes |
|---|---|---|---|---|
| 1769-L24ER-QB1B | 750 KB | 4 | Dual (DLR) | Embedded 16 DC in / 16 DC out, embedded 24V DC power supply |
| 1769-L24ER-QBFC1B | 750 KB | 4 | Dual (DLR) | Same embedded I/O as the L27ERM, no Integrated Motion |
| 1769-L27ERM-QBFC1B | 1 MB | 4 | Dual (DLR) | Embedded I/O + up to 4 motion axes -- this guide |
| 1769-L30ER | 1 MB | 8 | Dual (DLR) | 8 local modules, up to 3 banks |
| 1769-L30ERM | 1 MB | 8 | Dual (DLR) | 8 local modules, up to 4 motion axes |
| 1769-L33ER | 2 MB | 16 | Dual (DLR) | 16 local modules, up to 3 banks |
| 1769-L33ERM | 2 MB | 16 | Dual (DLR) | 16 local modules, up to 3 banks, up to 8 motion axes |
| 1769-L36ERM | 3 MB | 30 | Dual (DLR) | 30 local modules (the L37ERM/L38ERM support 31) |
8. Related Guides
| Guide | Description |
|---|---|
| ControlLogix 1756-L83E Setup | Enterprise controller for larger applications requiring chassis-based I/O. |
| CompactLogix 5069-L306ER Setup | Current-generation CompactLogix 5380 with 5069 local I/O. |
| 1734-IB8 POINT I/O Guide | Distributed I/O that connects to the CompactLogix 5370 via EtherNet/IP. |
Reference Documentation
The following Rockwell Automation publications were used as references for this guide.
| Publication | Description | Download |
|---|---|---|
| 1769-TD005 | CompactLogix 5370 Controllers Specifications Technical Data (November 2023) | |
| 1769-UM021 | CompactLogix 5370 Controllers User Manual |
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