TL;DR
A single workstation losing communication is almost always a network issue: cable, switch port, NIC, or IP conflict. Check hardware first, then software.
What you might see
- operator workstation showing all loops in communication timeout
- DeltaV splash screen cannot connect to control network
- control network switch showing no link to workstation port
- other workstations still connected normally
Likely causes
Ethernet cable or RJ-45 connector fault at the workstation or switch
Failed NIC or NIC driver error on the workstation
IP address conflict with another device on the DeltaV control network
Switch port fault or STP topology change blocking the port
Required tools
- Laptop or another PC for network diagnostics
- Ethernet cable (spare, for substitution test)
- Network switch administration access
Safety first
- Restarting DeltaV Station Manager on an operator workstation clears active alarm acknowledgments. Notify the operator before restarting the service.
- Do not reconfigure the DeltaV control network IP addressing without a change order. An incorrect IP on the network can disrupt communications to multiple devices.
Procedure
- 1
Check the Ethernet cable connection at the workstation NIC and at the control network switch port. Reseat both ends.[1]
- 2
Verify the switch port link LED is active. A dark port LED means no physical link.
- 3
Try a different switch port. If the link comes up on a new port, the original switch port has failed.
- 4
Open the Windows network adapter settings on the workstation. Confirm the NIC is enabled and showing an active link.[1]
- 5
Check the IP address configured on the NIC against the DeltaV network address plan. Confirm no duplicate IP exists on the network.
- 6
Run a ping from the workstation to the primary controller IP address. Packet loss indicates a network path problem.
- 7
If all hardware and IP checks pass, restart the DeltaV Station Manager service on the workstation.
Sources
Emerson Emerson DeltaV DCS (Distributed Control) general technical documentation, Emerson
Emerson DeltaV DCS general workstation network and communication procedures (general)
More guides for Emerson Emerson DeltaV
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Unplanned switchover means the primary controller faulted and transferred to the secondary. Review the event log to identify the fault type before restoring the secondary as hot standby.
How to fix an I/O card communication fault on an Emerson DeltaV DCS
A BAD I/O card status means field signals are not reaching the controller. Identify whether the fault is the card, the carrier backplane, or the fieldbus wiring.
Stop fixing the same fault twice.
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