Product Overview
The Siemens 6DD1662-0AC0 is a SIMADYN D CS8 communication support carrier module — the backplane-hosted chassis that accepts up to two plug-in communication modules (SS4, SS5x, SS52 family) and bridges them to the SIMADYN D rack’s L-bus so the PM5/PM6 CPU modules can exchange data with external devices. It is the smaller sibling of the CS7 carrier (6DD1662-0AB0, which accepts 3 submodules); the 6DD1662-0AC0 occupies the same 2-slot (40.64 mm) rack width and shares the same architecture, but populates only two submodule receptacles (X01–X02) instead of three. In a SIMADYN D rack next to a PM6 (6DD1600-0AK0), an EB1 power supply, EM11/IT41 I/O, and possibly a DS71 drive interface, the 6DD1662-0AC0 is the “face” that reaches outward — to a commissioning PC, to a PROFIBUS DP master/slave drive network, or to legacy SIMOVERT converters over USS.
Architecturally, the Siemens 6DD1662-0AC0 carries a dual-port RAM (16 KB per plugged-in submodule) that the communication modules and the CPU modules share — this is how a PM6 running D7-SYS C-code “sees” a PROFIBUS DP telegram or a DUST serial frame without polling. The carrier draws +5 V at ~400 mA from the rack backplane (fed by EB1), owns two diagnostic LEDs per submodule compartment (status + bus activity, meaning depends on which SSx is plugged), and passes the L-bus basic sampling time through for synchronization (though this feature is not used by the SS4/SS5/SS52 family itself). A test socket pair per receptacle (X10/X11, X20/X21) allows a forced reset from the front — test-only, not for runtime use.
The submodule ecosystem that the 6DD1662-0AC0 hosts is:
- SS4 (6DD1661-0AA0) — serial DUST (PC coupling: commissioning, TELEMASTER, CFC test mode, program download) + USS (SIMOREG/SIMOVERT drive converters); onto SS4 you further plug SS1 (20 mA current loop) or SS2 (RS-232).
- SS52 (6DD1661-0AB0) — PROFIBUS DP / MPI, 12 Mbps, 9-pin SM5, for coupling to SINAMICS S120, S7-400/300 masters, or ET 200 distributed I/O.
- SS5x — newer serial variants in the same plug-form.
Lifecycle: the Siemens 6DD1662-0AC0 went PM500, discontinued 1 Oct 2017, deleted without replacement per Siemens Industry Mall (“Product was deleted without replacement. If you need assistance please contact our local Siemens office”) — this is the critical point for spare strategy: there is no SINAMICS/TDC equivalent carrier that drops into a SIMADYN D rack. Once a 6DD1662-0AC0 fails, the only recovery path is secondary market or a full rack migration (PM6+CS8 → S7-1500T+et200+PN). Thousands of SIMADYN D racks in hot-strip mills, compressor antisurge, and fatigue rigs still run CS8 carriers, so the 6DD1662-0AC0 is purely a spare-demand SKU today.
Technical Specifications
| Parameter Name | Parameter Value |
|---|---|
| Product Model | 6DD1662-0AC0 |
| Manufacturer | Siemens |
| Product Type | SIMADYN D CS8 Communication Support Carrier Module |
| Submodule Capacity | Max. 2 plug-in comm modules (SS4, SS5x, SS52) |
| Dual-Port RAM | 16 KB per communication submodule |
| Diagnostic LEDs | 2 per submodule compartment (status + bus activity) |
| Backplane Bus | L-bus (to PM5/PM6 CPU modules) |
| Current Consumption | +5 V / ~400 mA (from rack EB1 backplane) |
| Space Requirement | 2 slots (40.64 mm rack width) |
| Receptacles | X01, X02 (submodule), X10/X11, X20/X21 (test reset only) |
| Rack Environment | SIMADYN D SR6 / SR12 / SR24 subrack |
| Net Weight | 0.355 kg |
| Packaging Dimensions | 273 × 274 × 44 mm (module envelope in subrack) |
| Operating Temperature | 0 … +60 °C (rack ambient, EB1-dependent) |
| Lifecycle Status | PM500 – Discontinued 1 Oct 2017, deleted without replacement |
| Companion CPU Module | 6DD1600-0AK0 (PM6), 6DD1600-0AF0 (PM6 variants), 6DD1600-0BAx (PM5) |
| Typical Submodule Pairing | SS4 (6DD1661-0AA0) + SS52 (6DD1661-0AB0) |
Main Features and Advantages
Carrier architecture with dual-port RAM offload
The Siemens 6DD1662-0AC0 is not a communication engine itself — it is the passive-active carrier that hosts up to two SSx communication modules and gives them a 16 KB dual-port RAM window each. This RAM is the magic: the SS52 (PROFIBUS DP) or SS4 (DUST/USS) DMA-feeds telegrams into the 16 KB, and the PM6 CPU reads/writes that RAM over L-bus without copying cycles. On a tandem-mill SIMADYN D rack where the PM6 is already at 80% scan on tension+looper+AGC, offloading DP-stack and UART interrupts to the +SS4 behind the 6DD1662-0AC0 keeps the PM6’s 0.5 ms task clean. Compare to a design where the CPU must bit-bang PROFIBUS — not possible on PM6.
Compact 2-submodule footprint vs. CS7
Choosing the Siemens 6DD1662-0AC0 over the CS7 (6DD1662-0AB0) is a rack-real-estate decision. Both occupy 2 slots (40.64 mm) — the CS8 simply leaves X03 unpopulated on the PCB. If the application only needs “one SS4 for PC/DUST commissioning + one for PROFIBUS DP to the drive line,” the 6DD1662-0AC0 is the correct SKU; speccing a CS7 wastes nothing electrically but costs more (when available) and leaves an unused X03 that fools panel audits into thinking a “missing module” alarm exists (the CS7 flags empty X03 in diagnostics; the 6DD1662-0AC0 doesn’t have X03 at all). For racks that need 3 paths (e.g., SS4 + + second for redundant DP to two S7-400 masters), you must take CS7, not the 6DD1662-0AC0.
The most common load-out on a Siemens 6DD1662-0AC0 in the field is X01=SS4, X02=. The SS4 runs DUST1 to a service laptop (CFC test mode, TELEMASTER trend, program download over serial at 19.2 k–115.2 k) and USS to a closet-full of legacy SIMOVERT Master Drives (cascaded USS over RS-485 daisy chain, the SS4’s RS-485 P/N on pins 5/17). The on X02 lands on PROFIBUS DP 12 Mbps — either as DP-V1 master to SINAMICS S120 bookshelves (if the plant modernised drives but kept SIMADYN D loop closure) or as DP slave to an S7-400/1500 that owns sequence. The 6DD1662-0AC0 carries both conversations simultaneously because each SSx has its own 16 KB DP-RAM and the carrier arbitrates L-bus access per PM6 task cycle.
