Woodward's MicroNet is a control platform that earns its place in turbine and critical-process control through modularity: the chassis stays, the modules define the machine. Reading the family as a system rather than a parts list is what makes retrofits and expansions sane — the I/O modules (5466 series), the Ethernet communication variants and the power supplies each answer one question about the plant they serve.
The I/O question: density and redundancy
The 5466 analog and discrete modules set the I/O economics: high-density combinations for panels where rail space is money, standard analog for conventional scopes, and TMR variants — analog combo and discrete — where the safety architecture demands voted I/O. One honest example of the family's reach sits at the distributed end: the 5466-031 LINKnet controller module, which extends MicroNet I/O across a network instead of across a backplane — the answer for plants whose measurement points live far from the chassis.
The network question: one port or two
The Ethernet variants differ by port count and speed — single-port 10BaseT for simple nodes, dual-port gigabit builds for redundant rings. The rule follows the plant's network philosophy: a node that must survive a cable cut gets two ports; a node that can ride a maintenance window gets one.
The power question: site reality
Power modules divide by input range — 88–132 VAC/100–150 VDC builds versus wide-range variants — and the selection is the site's electrical reality, not preference. Retrofit projects inherit their predecessor's supply; new plants pick the wide-range module and stop thinking about it.
The decision rule
Specify the chassis by the safety architecture (standard or TMR), the I/O by point count and location, the network by the redundancy promise, the power by the site. The platform lands in the plant's control hierarchy as the turbine-grade tier — one engineering discipline, one spare philosophy.
Can MicroNet modules mix TMR and standard in one chassis?
The architecture defines zones — TMR chassis run TMR modules for the safety scope, and mixing philosophies inside one voted backplane defeats the vote. Keep the safety scope pure; the non-safety I/O belongs in its own chassis.
When does LINKnet beat more I/O modules?
When the points are distant: pulling hundreds of wires to the chassis versus hanging a LINKnet node where the signals live. Distributed I/O is a wiring-cost decision, and the 5466-031 is its instrument.
