The ABB 1SAP170800R0001 is the CM578-CN PLC expansion module — a backplane-side add-on that lives in the PLCs & HMIs expansion rail rather than as a standalone controller. For a sourcing buyer, the order code is the only handle that matters when matching a BOM line, a replacement request, or a freight manifest entry, so the part number is the first thing to confirm against the PO before anything else gets touched. The only quantitative figure on the listing is a weight of 0.05 kgs, which tells the maintenance buyer this is a featherweight expansion slice — it ships in a small bag, slots into a spare-parts drawer without ceremony, and adds essentially nothing to the panel's mass budget. Every other electrical, protocol, and slot-compatibility detail for the CM578-CN sits in the ABB datasheet and isn't reproduced in the storefront spec line.
Sourcing and BOM-line posture
Because the listing carries no official cross-reference, there is no defensible drop-in alternative to quote from this evidence bundle. The closest class peer on file, 1SAP120600R0071, sits in the same PLC Expansion Modules category but at 0.13 kgs rather than 0.05 kgs — that weight gap alone is not a procurement decision (a buyer doesn't swap modules over grams), and the absence of electrical and protocol data on both parts means a true like-for-like second-source claim can't be grounded here. If a second-source is required for risk reduction, it has to be confirmed against the ABB cross-reference table, not inferred from class membership.