What this module is and why it matters for your BOM
6ES7135-6HB00-0DA1: isochronous mode, diagnostic alarms, channel-by-channel diagnostics (wire-break current, short-circuit voltage). Each output sources up to 30 V, max 90 mA from 24 V DC backplane; typ power loss 0.9 W. Important constraint: there is no channel-to-channel isolation. All outputs share a common reference. If your application requires galvanic separation between channels, this module won't provide it. The isolation tested value is 707 V DC only between the module and the backplane.
The closest same-function sibling is the 6ES7136-6AB00-0CA1. That module has 4 analog output channels and includes HART protocol support. The 6ES7135-6HB00-0DA1 has only 2 channels and no HART. If your application needs HART or four outputs, the 6ES7136-6AB00-0CA1 is the correct choice. If you need oversampling and high-speed updates (< 50 µs per channel), the 6ES7135-6HB00-0DA1 wins — the 6ES7136 does not support oversampling. Physically, both mount on the same base units (BU type A0 or A1), so the mechanical fit is identical. The wiring scheme differs because the 6ES7135 is 2-channel 4-wire while the 6ES7136 is 4-channel 2-wire. A panel wired for the 6ES7136 would need re-termination to use the 6ES7135, and vice versa.
Production status and sourcing
For a BOM freeze, confirm the base unit number (BU type A0 or A1) and that the firmware version is at least FS06 to access all hardware functions. The module supports I&M data (I&M0 to I&M3) for asset management.
For voltage outputs, maximum shielded cable length is 200 m; for current outputs, up to 1 000 m. For capacitive loads (max 47 nF over 20 m), output settling time is 0.05 ms. Channel status and diagnostics via green/red LEDs: green per channel, green/red DIAG, red per channel.