If you are standing in front of a failed module in a CENTUM cabinet and need to order a replacement, the first problem is usually not availability. It is working out exactly which part you are looking at.
Which code is the one you need
A Yokogawa module label typically carries three separate identifiers:
- Model code — the ordering code. On CENTUM VP hardware this generally follows a pattern such as
AAI143-S00: three letters, three digits, then a suffix after the hyphen. - Style or revision code — often
S1,S2. Indicates hardware revision. Matters for compatibility, but is not the ordering code. - Serial number — unique to the unit. Useful for traceability, useless for ordering.
The suffix after the hyphen is not decoration. On many I/O modules it encodes termination type or signal configuration, so AAI143-S00 and AAI143-H00 are not interchangeable. Quote the full string.
Reading the model code structure
| Prefix pattern | Typical function |
|---|---|
| AAI… | Analog input modules |
| AAO… | Analog output modules |
| ADV… | Digital input/output modules |
| ALR… | Serial communication |
| ALE… | Ethernet communication |
| ANB… | Bus interface and node units |
When the label is damaged or missing
- Check the engineering database. The CENTUM engineering station holds the hardware configuration for every node, giving the module type by node and slot.
- Check the as-built documentation. Cabinet layout drawings and I/O schedules usually list module codes by slot position.
- Photograph the module and its neighbours. Modules in one cabinet often share a family; a clear photo is usually enough for identification.
Three checks worth thirty seconds
- Revision compatibility. Later revisions are usually backward compatible — but not always, particularly across the CS 3000 to VP transition.
- Configured or generic. Some modules carry site-specific configuration that must be reloaded after replacement.
- Termination arrangement. The module and its termination board are a matched pair.
A note on obsolete codes
If a model code returns nothing on current Yokogawa material, the module is most likely out of production rather than mislabelled. That does not mean it is unobtainable — it means supply has moved to the surplus and refurbished market.
Not sure what you are looking at? Send a photo of the nameplate to sales@neodriveai.com. We will identify the part and tell you what is available.