- ABB identifies DSDX451L as an S400 digital expansion unit.
- It combines 20 digital 24 V DC inputs with 12 separated relay outputs.
- The L suffix denotes the low-current relay-contact version with model-specific load limits.
DSDX451L is an ABB remote I/O expansion unit for documented Advant Controller 450 S400 assemblies.
Its mixed I/O arrangement extends the companion digital basic unit while retaining 24 V input service and isolated low-current relay switching.
Before installation or replacement, verify the companion basic unit, expansion connection, L-suffix contact loading, field supply, rack wiring, and controller channel map.
Availability, condition, price, and shipping time for DSDX451L are confirmed during quotation.
ABB DSDX451L Remote I/O Expansion Unit Manuals, Datasheets, Links
Important Notice: Other accessories, manuals, cables, calibration data, software, etc. are not included with this equipment unless listed in the above stock item description. All prices are shown in USD.
- The L version uses relay contacts intended for low-current output circuits.
- The documented maximum is 200 mA, subject also to the applicable 5 VA or 5 W limit.
- The recommended minimum load is 5 mA or 0.05 VA, which must be considered during troubleshooting.
- DSDX451L operates as an expansion unit rather than a standalone S400 basic unit.
- The companion unit supplies the documented expandable mixed-I/O arrangement.
- Expansion connectors, terminal references and saved channel assignments must remain aligned with the installed pair.
- ABB lists TU407 for specific S400 mixed-I/O combinations that include DSDX451L.
- The migration unit is designed to retain the existing S400 field-wiring connectors and footprint.
- Verify the complete basic-plus-expansion combination before selecting the S800 termination assembly.
- Expansion of 24 V digital input capacity in ABB S400 I/O stations.
- Low-current relay switching for isolated 24 to 240 V AC or DC control circuits.
- Mixed digital input and relay-output service in documented Advant Controller 450 assemblies.