Good morning, I am currently working with a system involving a 1756 L73 PLC and Supervisor on EN2TR modules. While most functions are running smoothly, there is an issue with the EN2TR modules. The primary PLC (EN2TR (1)) is set to be the active supervisor with a precedence level of 20, but this setting is also being applied to the secondary PLC (EN2TR (2)). Resetting EN2TR (2) causes the primary PLC (EN2TR (1)) to take over as the primary supervisor, but full redundancy cannot be achieved until EN2TR (2) has the same IP address as EN2TR (1). Once the IP addresses match, EN2TR (2) becomes the primary supervisor. How can I ensure that EN2TR (1) remains the master supervisor in the system? Thank you in advance for any assistance provided.
If you are having trouble with language, let me explain clearly: You are using a ControlLogix Redundancy system with DLR connections to both chassis. Initially, both EN2TRs have the same IP address, but during the Sync process, the secondary address increments by 1. Your goal is to always have the DLR supervisor on the Primary chassis. If the statements above are accurate, it is important to note that DLR operates differently. Both the Primary and Secondary EN2TR modules need to have the same DLR Supervisor precedence. If there are no other DLR supervisors, then the module with the smaller MAC address will become the Active supervisor. If you prefer a different setup, you will need to designate another DLR device as a supervisor.
In response to Contr_Conn's query, it seems that there may be some confusion regarding the ControlLogix Redundancy system with DLR setup. Both EN2TR modules initially have the same IP address, but during the Sync process, the secondary address increments by 1. The goal is to always have the DLR supervisor on the Primary chassis. However, it is important to note that for DLR to function properly, both Primary and Secondary EN2TR modules must have the same DLR Supervisor precedence. If there are no other DLR supervisors present, the module with the smaller MAC address will become the Active supervisor. If this setup is not desired, another DLR device needs to be designated as a supervisor. Upon swapping the EN2TR modules, the status "Active" is displayed on the EN2TR in the main PLC. You can see this configuration in the image below, where the left EN2TR is installed in the main PLC.
As previously mentioned, the MAC address ending in CB:0D is lower than CC:15, which means the module with the higher MAC address becomes the DLR supervisor. It is important to note that both redundancy chassis are identical. When performing a switchover, the new primary chassis (formerly the secondary) will not automatically become the DLR supervisor unless you power off the former primary rack. The same issue arises if both chassis are powered on simultaneously – the primary chassis cannot be determined, whereas the DLR supervisor module is known. To address this issue, consider having a DLR supervisor located outside of the redundancy chassis.
Contr_Conn explained that the MAC address with the ending CB:0D is lower than CC:15, making the second module the DLR supervisor. It's important to note that both redundancy chassis are identical. When initiating a switchover, the new primary chassis will not automatically become the DLR supervisor unless you power off the former primary rack. The same applies if both chassis are powered on simultaneously - the primary chassis is uncertain. To avoid this issue, consider having a DLR supervisor separate from the redundancy chassis. Thank you for the clarification.
It sounds like you might be dealing with a configuration issue here. If you want to establish EN2TR (1) as the master supervisor by default, it could be beneficial to look into the redundancy settings. Check to see if the 'Active Supervisor Precedence' for EN2TR (1) is set higher than for EN2TR (2). If they're set at the same level, your system may be confusing the two. Also, ensure that your EN2TR modules are properly synchronized; in redundant systems, time synchronization can have a significant impact on which PLC assumes Master control. If these steps don't resolve the issue, you may need to delve into the firmware or even hardware troubleshooting.
Hi there! Sounds like a challenging situation. To help maintain the desired redundancy and prevent EN2TR (2) from becoming the primary, I'd recommend checking if there's any form of automatic role swapping or load balancing feature enabled in the system settings. This could be leading to your secondary PLC taking precedence. If so, disabling this feature should keep EN2TR (1) as the primary supervisor unless it fails. Additionally, ensure that your EN2TR (2) (secondary) has a lower precedence level assigned in its settings than EN2TR (1) to help maintain hierarchy. Hope this helps!
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Answer: Answer: To ensure EN2TR (1) remains the master supervisor in the system, you need to make sure that both EN2TR modules have unique IP addresses. Once EN2TR (2) has a different IP address from EN2TR (1), full redundancy can be achieved with EN2TR (1) as the primary supervisor.
Answer: Answer: The issue of the setting for the primary PLC being applied to the secondary PLC could be due to both EN2TR modules having the same IP address. To address this, ensure that EN2TR (1) and EN2TR (2) have unique IP addresses to prevent conflicts in the system.
Answer: Answer: To configure the EN2TR modules for full redundancy and maintain the correct supervisor hierarchy, make sure that EN2TR (1) is set as
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