The Omron SRT1-ID04 is a remote terminal module in the PLC I/O & Expansion Modules category, designed to extend the I/O count of an Omron control system over a fieldbus link rather than a local backplane. It is a mature product, meaning it has been in the field long enough that the installation base is well understood and spares are still available through distribution channels.
There is no official successor or replacement part for the SRT1-ID04. If you are replacing a failed unit, the direct order code is the correct path. If you are designing a new system and want the latest hardware, look at the current Omron remote I/O family — the SRT1-ID04 will not be the recommended starting point for new builds.
What the SRT1-ID04 is not — and what that means for your BOM
The evidence does not list an input voltage specification, a channel count, or a fieldbus protocol for the SRT1-ID04. That is unusual for a PLC I/O module and suggests this may be a specific variant or a remote terminal with a fixed configuration. Before committing the BOM line, confirm the mating bus coupler and the I/O map — the SRT1-ID04 may require a specific master module or a particular revision of the Omron remote I/O firmware. Compared to the SRT1-ID08, the difference is likely in the I/O density — the ID08 designation suggests 8 points versus the ID04's 4. Without a datasheet on record, the pinout and power draw cannot be assumed to match. If you are swapping between the two, verify the backplane current budget and the field wiring terminal assignments.
Where to source the SRT1-ID04
No stock-holding claim is made — each order is handled on a per-RFQ basis.