What you're dealing with
The TM171DWAL2U is a Modicon M171 display module — white front face, monochrome LCD, four keys, a real-time clock onboard. Runs off 12 VDC from an external source, draws about 5 W, and carries CE marking. IP40 on the front face only, so it's panel-mount with protection from finger contact but not water jets.
What about an alternative?
No direct pin-compatible drop-in replacement surfaced in the records. If you're redesigning a panel, you'll want to look at current Modicon HMI or display products — but the form factor and 12 VDC supply might not translate straight across. Your best bet is to send the BOM requirements and we can cross-check against what's available on the surplus market.