Description
The Siemens 6ES7 390-0AA00-0AA0 is a bus connector accessory manufactured by Siemens AG, belonging to the SIMATIC S7-300 automation system peripheral family. Classified as an IM-bus (Interface Module bus) connector, it is the DIN-rail-mountable 25-pin D-Sub female terminator used to land the IM bus cable between an S7-300 central rack (equipped with IM 360 master) and one or more expansion racks (equipped with IM 361 slaves)—or between the two halves of an IM 365 compact pair. Unlike the more familiar PROFIBUS DP DB9 bus connectors (6ES7 972-… series), the 6ES7 390-0AA00-0AA0 speaks the S7-300 internal IM bus protocol, carrying both data and the 5 V/24 V auxiliary supply that lets the IM 361 draw power from the IM 360 without a local PS307. The “-0AA00” suffix denotes the variant without a PG (Programming Device) pass-through socket; the sibling 6ES7 390-0AB00-0AA0 adds that PG port for on-rack laptop connection without unplugging the IM cable.
h2 Application Scenarios
A pulp & paper mill in Scandinavia runs a wet-end stock-prep line controlled by an S7-300 CPU 315-2 DP in the main MCC room, with two expansion racks (each IM 361 + 3×SM321 + 2×SM322) located 8 m away in a local IO closet on the machine floor—too far to backplane-extend, too close to justify a full PROFIBUS remote-I/O string. The original install used a 6ES7 368-3BH00 10 m IM-bus cable between IM 360 (rack 0) and the first IM 361 (rack 1), and another 6 m cable to rack 2. At the rack-0 end and each expansion-rack end, a Siemens 6ES7 390-0AA00-0AA0 is DIN-screwed to the rail just below the IM module, giving the 25-pin D-Sub hood a stable home that doesn’t stress the IM module’s own connector pins. Ten years in, a maintenance sweep found the rack-1 6ES7 390-0AA00-0AA0 with a cracked D-sub shell from a panel brush incident—the IM bus still talked, but vibration was working the pins loose. The tech swapped in a spare 6ES7 390-0AA00-0AA0 in five minutes: unscrew the old from the DIN rail, unplug the 368 cable, click the new one down, replug, done. No rack power-down (IM 360/361 tolerate hot IM-bus reconnect on the connector side), no rewiring, no PG-socket confusion because this line doesn’t need a laptop tapped into the IM bus—the -0AA00 “no PG” version is exactly what the original BOM specified. For plants still running multi-rack S7-300s installed in the 2000s, the 6ES7 390-0AA00-0AA0 is one of those “five-euro part that stops a three-hour shutdown” items.
h2 Parameter
| Main Parameters | Value/Description |
|---|---|
| Product Model | 6ES7 390-0AA00-0AA0 (also listed 6ES7390-0AA00-0AA0) |
| Manufacturer | Siemens AG |
| Product Category | IM-Bus Connector (S7-300 rack expansion accessory) |
| Connector Type | 25-pin D-Sub female (mates with 6ES7 368-3… IM bus cable hood) |
| PG Pass-Through | None (no PG/OP socket; -0AB00 sibling has it) |
| Mounting | Screw-fasten to 35 mm DIN rail (separate from rack slot) |
| Compatible IM Modules | IM 360 (master), IM 361 (slave), IM 365 (compact pair) |
| Mating Cable | 6ES7 368-3BC01 / 3BH00 / 3BB00 etc. (0.5 / 1 / 2.5 / 5 / 10 m) |
| Max IM-Bus Length | 10 m (IM 360↔IM 361); 0.8 m (IM 365 only) |
| Signal Carried | IM bus data + 5 V (from IM 360) + 24 V aux (to IM 361) |
| Operating Temp | 0 °C to +60 °C |
| Mechanical Life | D-Sub mating cycles ≥ 500 (typical) |
h2 Technical Principles and Innovative Values
Innovation Point 1: DIN-Rail Separation from the Rack Slot. The Siemens 6ES7 390-0AA00-0AA0 does not consume a slot in the S7-300 rack—it screws to the DIN rail independently, usually positioned just below or beside the IM 360/361 module. This means the cable’s pull-force and panel-brush knocks land on the DIN-mounted connector shell, not on the IM module’s PCB-backplane pins. In vibrating environments (paper machine, crusher, turbine skid), this mechanical decoupling extends IM module life noticeably.
Innovation Point 2: PG-Less Variant for Closed Cabinets. The “-0AA00” (no PG socket) vs “-0AB00” (with PG socket) split is a thoughtful Siemens detail. Many production cabinets have a “no outside-laptop-pass-through” policy for cyber-security or dust-ingress reasons; the 6ES7 390-0AA00-0AA0 closes that door physically—there’s simply no D-Sub pass-through port to plug a PG into without first undoing the 368 cable. For legacy S7-300 fleets in pharma/nuclear where the BOM was frozen decades ago, the -0AA00 is the correct restoration part.
Innovation Point 3: 25-Pin Density Carrying Power + Data. The IM bus isn’t just data lines—the IM 360 regenerates 5 V from the rack’s PS307 and pushes it down the 368 cable, alongside 24 V aux, so the IM 361 in the expansion rack doesn’t need its own 5 V PS307 (just a PS307 24 V for the SM cards). The 6ES7 390-0AA00-0AA0‘s 25-pin pinout carries all of this—4 data pairs + power + shield drain—in one D-Sub instead of two separate connectors. That’s one less failure point per expansion rack.
h2 Application Cases and Industry Value
A water-treatment works in the UK operates three S7-300 stations along a 2 km trunk sewer—each station has a CPU 314-2 DP in rack 0, plus one IM 361 expansion rack 6 m away in a separate pump-bay cubicle, linked by a 6ES7 368-3BB00 2.5 m IM-bus cable terminated in a Siemens 6ES7 390-0AA00-0AA0 at each end. During a cabinet washdown (high-pressure fresh water, yes, against procedure), the rack-1 connector shell took a glancing hit and the D-sub latch cracked; the IM bus stayed up because the pins still seated, but the duty engineer flagged it on the weekly walk-round. Swapping the 6ES7 390-0AA00-0AA0 took longer to find the spare in the van than to fit it—five minutes DIN-unscrew, cable unplug, new one on, replug, DIN-screw. Post-incident review noted two things: first, the 6ES7 390-0AA00-0AA0‘s separate DIN mounting meant the IM 361 itself was unscathed—if the D-sub had been integral to the IM module, they’d have been replacing a £400 IM 361 instead of a £12 connector; second, the -0AA00 “no PG” variant meant the washdown crew literally couldn’t have plugged a laptop in if they’d tried, which satisfied the site IT audit. The station superintendent’s verdict: “boring part, wrong one to be out of stock.”
h2 Related Product Combination Solutions
A multi-rack S7-300 setup around the Siemens 6ES7 390-0AA00-0AA0 typically pulls from this short list:
- Siemens 6ES7 360-3AA01-0AE0 (IM 360): Master interface module in the CPU rack (rack 0); sources 5 V down the IM bus, mates to the 6ES7 390-0AA00-0AA0 at the rack-0 end.
- Siemens 6ES7 361-3CA01-0AA0 (IM 361): Slave interface module in expansion rack(s); receives 5 V from IM 360 via the 368 cable and the 6ES7 390-0AA00-0AA0 at the expansion end; needs its own PS307 24 V for local SM cards.
- Siemens 6ES7 365-0DA01-0AA0 (IM 365): Compact master+slave pair (0.8 m fixed cable, no separate 368 needed); each half still lands on a 6ES7 390-0AA00-0AA0 if you want DIN-mount strain relief, though many leave the hood floating on IM 365 since the cable is short.
- Siemens 6ES7 368-3BH00-0AA0: 10 m IM bus cable (the most common length), D-Sub male-to-male, plugs into the 6ES7 390-0AA00-0AA0 at each end. Also available in 0.5 m (3BC01), 1 m (3BD01), 2.5 m (3BE01), 5 m (3BF00).
- Siemens 6ES7 390-0AB00-0AA0: The PG-socket sibling of the 6ES7 390-0AA00-0AA0—identical except it adds a front-facing 25-pin PG pass-through. If your BOM says -0AA00, don’t substitute -0AB00 without checking the cabinet access policy—some auditors flag the extra port.
- Siemens 6ES7 307-1KA00-0AA0 (PS307 5 A): The 24 V / 5 A supply that typically lives in the IM 361 expansion rack (CPU rack 5 V feeds IM 360 and supplies 5 V down-cable; expansion rack covers its own SM-card 24 V draw).
- Siemens 6ES7 321-1BH02-0AA0 (SM321 16DI): Typical DI card populating the IM 361 expansion rack that the 6ES7 390-0AA00-0AA0/IM-bus is ultimately serving.