The 6ES7138-4DF11-0AB0: It can send and receive up to 32 bytes per message with certain IM151-1 versions (otherwise 8 bytes). Parity is selectable as none, odd, or even, but USI only allows even. There's reverse polarity protection on L+, and isolation between the serial port and the backplane.
I've seen folks wonder if the 6ES7138-4DE02-0AB0 (a counter module) is a drop-in — it's not. That part is 30 mm wide, has digital I/O and counter inputs, and does not support serial protocols at all. No wiring swap will make this do the other's job; they're built for completely different tasks. Stick with the right module for the right port.
Qualified to order against an RFQ; we can source this for your BOM line. No need to hunt for obsolete substitutes — it's alive and well.