1783-SFP100T-C Compatibility with Allen-Bradley Stratix 5700 1783-BMS20CL

Industrial Ethernet networks often use copper SFP modules to connect switches to nearby devices through standard RJ45 Ethernet cabling. However, the supported data rate depends on the specific SFP module and the switch port, not simply on the physical RJ45 connector.

In this case, a customer reported a problem when installing a 1783-SFP100T-C module in an Allen-Bradley Stratix 5700 1783-BMS20CL switch. Engineering feedback indicated that the copper port supports only 100BASE operation. This behavior is consistent with the 100BASE-T specification of the corresponding 1783-SFP100T module family.

1. Customer Compatibility Inquiry

The customer reported that the 1783-SFP100T-C module was not meeting the expected operating requirements when connected to a Stratix 5700 1783-BMS20CL switch. The engineering team identified the port's supported speed as the key limitation.

The important point is to distinguish a speed limitation from a module recognition or hardware failure. If the application requires a 100Mbps copper connection, 100BASE operation may be the expected result. If the customer requires 1Gbps, the selected module and switch port must support Gigabit Ethernet.

2. What Is the 1783-SFP100T Copper SFP?

The Rockwell Automation 1783-SFP100T is a Fast Ethernet copper SFP module. It provides an RJ45 interface for connecting Ethernet equipment through twisted-pair copper cabling.

These specifications show that the module is designed for Fast Ethernet rather than Gigabit Ethernet. Its RJ45 connector does not imply support for 10/100/1000Mbps operation. The actual supported speed is determined by the module's internal electronics and product specification.

3. Stratix 5700 1783-BMS20CL Port Capabilities

The 1783-BMS20CL is a 20-port managed industrial Ethernet switch in the Stratix 5700 family. Rockwell Automation lists 16 10/100Mbps RJ45 ports, two 10/100Mbps SFP ports, and two combination ports that support RJ45 or Mini-GBIC connections.

The switch's port specifications are important when selecting an SFP module. A 100BASE-T copper SFP is aligned with a Fast Ethernet connection, while a Gigabit Ethernet SFP requires a compatible GE SFP slot and a switch model that supports that operating mode.

4. Why Does the Copper Port Only Support 100BASE?

The 1783-SFP100T is specifically designed for 100BASE-T operation. It does not provide 1000BASE-T Gigabit Ethernet capability. Therefore, a connection operating at 100Mbps is consistent with the module's published specifications.

Several factors should be separated when evaluating the reported speed:

• Module capability: The 1783-SFP100T is a 100Mbps Fast Ethernet module.

• Switch port capability: The 1783-BMS20CL has 10/100Mbps SFP interfaces.

• Remote device capability: The connected equipment must support a compatible 100BASE-T connection.

• Application requirement: The required speed must match the capabilities of both endpoints.

5. 100BASE-T vs. 1000BASE-T Copper SFP

Although 100BASE-T and 1000BASE-T copper SFP modules both use RJ45 connectors, they serve different Ethernet speed requirements. Selecting the correct type is essential for industrial network upgrades and equipment integration.

A 1000BASE-T SFP should only be selected when the switch has a compatible Gigabit Ethernet SFP slot. The 1783-BMS20CL's 10/100Mbps SFP interfaces should not be assumed to support Gigabit SFP operation.

6. Firmware and Installation Requirements

Rockwell Automation's Stratix 5700 technical documentation lists the 1783-SFP100T as a supported SFP option for applicable Stratix 5700 models. The documentation also specifies a minimum Stratix 5700 firmware revision of 8.001 for this module.

Before deployment, confirm the installed firmware version and the exact SFP port being used. The module must be installed in a supported SFP or combination port, and the remote Ethernet device must be configured for a compatible connection.

Recommended checks include:

1. Confirm the complete switch catalog number is 1783-BMS20CL.

2. Verify that the module is installed in a supported SFP or combination port.

3. Check that the Stratix 5700 firmware meets the documented minimum requirement.

4. Confirm that the remote device supports 100BASE-T operation.

5. Check the Ethernet cable and RJ45 connection.

6. Review the switch interface status, speed, duplex mode, and error counters.

7. How to Select the Correct Copper SFP

The correct copper SFP should be selected according to the required Ethernet speed and the actual port capabilities of the industrial switch.

For an application requiring 100Mbps, a compatible 100BASE-T copper SFP is appropriate. For an application requiring 1Gbps, both the switch port and the selected copper SFP must support 1000BASE-T. A Gigabit module cannot overcome a switch port's hardware speed limitation.

8. Conclusion