Tel: 
Email: 
WhatsApp: Description
Technical Specifications (For Spare Parts Verification)
- Product Model: 3ASC25H219B DATX133
- Manufacturer: ABB
- System Platform: AC 800M with S800 I/O system
- Compatible I/O Modules: Standard S800 analog and digital modules (e.g., AI810, AO810, DI810, DO810)
- Wiring Type: Screw-terminal field connections (removable terminal blocks)
- Backplane Interface: Connects to S800 I/O rail via DIN 41612 connector
- Power Distribution: Carries +5 VDC logic power and ±15 VDC/24 VDC auxiliary power from backplane to I/O module
- Diagnostic Support: Passes module status LEDs to front panel; no active electronics
- Mechanical Form: Half-width base unit occupying one slot in S800 I/O chassis
- Certification: CE, UL, CSA compliant (original manufacturing batch)
- Replacement Part Number: Officially superseded by DATX133-1 (3ASC25H219C) with improved terminal retention
System Role and Downtime Impact
The DATX133 terminal base is a passive but essential component in ABB’s S800 I/O architecture. It serves as the mechanical and electrical bridge between plug-in I/O modules and both the field wiring (via screw terminals) and the system backplane (via edge connector). While it contains no active circuitry, its integrity directly affects signal reliability. A cracked housing, loose terminal block, or corroded backplane contact can cause intermittent signals, channel dropouts, or complete module miscommunication—leading to false alarms, control loop instability, or safety system faults. In redundant or SIL-rated applications, such failures may trigger unnecessary trips. Because the DATX133 is often installed in large quantities per system, a systemic issue (e.g., batch-related terminal fatigue) can cascade across multiple I/O points.
Reliability Analysis and Common Failure Modes
Although passive, the DATX133 is subject to mechanical and environmental wear over decades of service:
- Terminal block loosening: Repeated thermal cycling or vibration can cause screw terminals to back out, increasing contact resistance or causing open circuits.
- Plastic housing embrittlement: UV exposure (in outdoor panels) or prolonged heat accelerates polymer aging, leading to cracks during module insertion/removal.
- Backplane contact oxidation: Humidity ingress causes corrosion on DIN 41612 pins, resulting in poor power or data transmission to the I/O module.
- Latch mechanism fatigue: The plastic clip that secures the I/O module can break after repeated handling, risking module dislodgement.
Preventive measures include periodic torque checks on terminal screws (per IEC 60947), visual inspection for housing cracks, cleaning of backplane contacts with isopropyl alcohol, and avoiding excessive force during module replacement. Given its role as a signal gateway, even minor degradation can manifest as elusive intermittent faults.
ABB 3ASC25H219B DATX133
Lifecycle Status and Migration Strategy
ABB has phased out the original DATX133 (3ASC25H219B) in favor of the revised DATX133-1 (3ASC25H219C), which features enhanced terminal block retention and improved material durability. While the two are mechanically and electrically compatible, new production of the -B revision has ceased.
For existing systems:
- The DATX133-1 can be used as a direct replacement without rewiring or configuration changes.
- Existing terminal blocks (e.g., TB840A) are typically reusable if undamaged.
Long-term, facilities modernizing their AC 800M I/O should consider migrating to the S800 Compact or S900 I/O platforms, which offer higher density and integrated diagnostics—but this requires chassis and cabling updates.
In the interim, maintaining a small inventory of verified DATX133 or DATX133-1 bases for critical I/O slots is prudent. Given that failure is mechanical rather than electronic, proper handling and inspection protocols significantly extend service life. However, for systems approaching end-of-life, including terminal base obsolescence in the overall migration plan is essential.
