ABB CHBX01L 2VAA008574R1 Left-side Horizontal Bus Expander

I. Basic Model Information
Full part number: CHBX01L / 2VAA008574R1
Brand: ABB
Product name: Left Horizontal Bus Extender
System: Symphony Plus (S+ SD HN800 I/O) DCS system, mainstream process control hardware for thermal power, chemical, and nuclear power
Position: Left backplane bus extension unit of HN800 local I/O rack, used to extend the horizontal high-speed bus of the rack and expand I/O slots

Model Interpretation
CHBX = Compact Horizontal Bus Extender
01 = Standard first-generation hardware version
L = Left (the corresponding model on the right is CHBX01R)
2VAA008574R1: ABB original material order number

Core Functions
Leftward expansion of HN800 high-speed backplane
When the right expansion slot of the standard HN800 I/O row is insufficient, install CHBX01L to extend the leftward backplane bus, and expand up to 8 I/O module slots (standard SD I/O cards such as AI/AO/DI/DO).
Bus + 24VDC power supply synchronous distribution
Simultaneously transmit the 1Gbps high-speed HN800 data bus and 24VDC module power supply. The I/O on the extended side does not require an additional power base.
Redundant bus link support
Compatible with system redundancy architecture. The main/backup bus automatically switches. The fault switching time is less than 10ms, ensuring continuous process control without interruption.
Plug-and-play without configuration
The hardware can be directly plugged into the backplane for identification. The controller automatically scans the newly added I/O and does not require dip switches or separate downloading of extension parameters.
Overall status diagnosis
Panel LED indicators: power, bus operation, link failure. Fault information is uploaded to the Symphony Plus operation station for alarm.

Key Electrical and Mechanical Parameters Table
Parameters Specifications
Power Supply 24VDC ±15%, supplied by the HN800 backplane
Power Consumption Normal state ≤ 3W, full load ≤ 5W
Bus Rate Highest 1Gbps on the HN800 backplane bus
Expansion Slot Capacity Up to 8 standard SD I/O modules
Installation Method Horizontal installation using 35mm standard DIN rail
Operating Temperature -10℃ ~ +55℃; Storage – 40℃~+70℃
Humidity 5%~95% RH, no condensation
Protection Grade IP20 (installed in the control cabinet)
Dimensions 220 × 160 × 50 mm
Weight Approximately 0.8kg
Certifications CE, UL, RoHS, IEC61131-2

Hardware Interface Description
DB36 Female Bus Socket
Connects to the HN800 host frame backplane to transmit high-speed data + 24V power;
Green terminal block L+ / L- / SA / SB
External redundant bus auxiliary wiring, bus shielding grounding terminal;
Right-side expansion card slot
Used for connecting the next group of HN800 I/O module rows;
DIN rail clip: Quick assembly, supports horizontal cabinet arrangement.

Series Identification (CHBX01L / CHBX01R)
CHBX01L 2VAA008574R1: Left-side expansion, the host frame bus extends to the left
CHBX01R 2VAA008575R1: Right-side expansion, the host frame bus extends to the right
The hardware functions are the same, only the installation direction and interface layout are opposite, and they cannot be interchanged.