What you're specifying
The ABB 1SAP170400R0001 is a PLC expansion module in the PLCs and Accessories line, a 0.04 kg slice that drops onto the controller's local bus to widen I/O or comm capacity without rebuilding the panel footprint. It's the kind of part you spec on the BOM as a line item — order code 1SAP170400R0001 — when the base CPU has run out of channels and the cabinet still has DIN rail spare.
Where the class fits on the panel
PLC expansion modules like this one sit to the right (or below) the CPU on the same backplane or terminal strip, sharing the controller's fieldbus addressing and power budget rather than acting as a standalone node. At 0.04 kg it's a featherweight block — wiring, not mass, is what governs the install time on these, so plan the spring-cage terminals and labeling before the module lands on the rail.
Second-source posture
ABB peers in the same PLCs and Accessories / PLC Expansion Modules class include 1SAP120600R0071 at 0.13 kg, 1SBP260100R1001 at 0.09 kg, and 1SVR440721R1000 at 0.09 kg — any of which can be cross-shopped against this order code on a multi-vendor approved BOM.
Sourcing close
With a confirmed ABB order code and a sub-half-kilo shipping mass, 1SAP170400R0001 is the kind of part that's quoted to order against an RFQ — pull the line into the PO with the exact code and let procurement confirm the current lead and any applicable compliance paperwork before release.