Schneider 490NAC0100 Hot Standby Copper Adapter for Modicon M580 Redundant Processors

490NAC0100: The Hot Standby Copper Adapter for Modicon M580

The 490NAC0100 is the hot standby adapter that connects two processors in a Modicon M580 hot standby architecture. Its whole purpose is the 1 Gbit/s RJ45 link between the HSBY processors — that link is what lets the standby processor track the running one closely enough to take over without losing process state.

It is a copper adapter, range compatible with Modicon M580, product compatibility with M580 HSBY CPU, metal construction, one RJ45 electrical connection, transmission rate 1 Gbit/s.

What Makes Hot Standby Different from Warm Standby

In a hot standby architecture both processors run the same application. The standby is not idle waiting to be promoted — it is executing, which is what allows takeover to be fast enough for the process.

That places a hard requirement on the link between the two processors: it has to carry the process state continuously enough that a takeover does not restart the application. A 1 Gbit/s link is what makes that possible, and it is why this adapter is a functional part of the redundancy architecture rather than an accessory.

M580 Hot Standby Adapters: Copper and Fiber

The hot standby adapter family splits by transmission medium, and the choice is a distance question rather than a performance one — both carry the processor-to-processor link at the same rate:

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Commissioning a Hot Standby Pair

With both processors executing the same application, commissioning has a step a single-processor system does not: verifying that the pair agrees and that the link is carrying state correctly.

• Confirm both HSBY processors run the identical application version.
• Verify the pair reports as synchronised before the process is placed in automatic.
• Test the failover deliberately, under controlled conditions, rather than waiting for a real failure.
• Confirm the adapter link is stable — a link that drops state produces an unsynchronised pair.

Why the Link Belongs in the Spares Strategy

On an M580 hot standby installation the adapter is the single component whose failure removes the redundancy entirely — the machine keeps running on one processor, but the fault tolerance the architecture was specified for is gone. That makes it a more consequential spare than its physical size suggests.

Supply & terms: Stock status: In Stock · Condition: New · Warranty: One Year · Origin: France. Listed by AutoDCS Tech Parts Team · Last updated 2026-10-07.

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