Description

## I. Product Positioning
Full Model Name: DSBC172 57310256-EL. It belongs to the ABB Advant OCS / S800 I/O distributed DCS system and serves as a dedicated terminal base for DI digital input (matched with DI572 16-channel AC digital input card). It is a 16-channel discrete wiring base specially designed for DCS systems and auxiliary control systems of power generating units in thermal power plants, hydropower plants and transformer substations. When used together with REF615 comprehensive protection relays and SACO16D1 alarm units, it collectively collects passive contact signals including on-site circuit breaker status, protection tripping actions, fan faults and local field signals, realizing modular I/O wiring and bus communication switching inside control cabinets. The product has obtained CE industrial certification and is a standard spare part for thermal power industries.

Code Definition: 57310256-EL stands for the ordering variant with European-standard spring terminals, while the standard model 57310001-KD adopts screw terminals; EL denotes spring-type quick-connect wiring base. The DSBC series integrates S800 I/O backplane bus and terminal base into one single unit.

Installation: Snap-on mounting onto standard DIN35 rails for side installation inside control cabinets. Multiple bases can be plugged and interconnected on the same rack for network configuration.

II. Hardware and Electrical Specifications
### 1. Power Supply Specifications
Operating power supply for module: DC24V±20% (fed from redundant 24VDC power supply inside system cabinets)
Power consumption per single base: ≤4.8VA
Dielectric Withstand Voltage: Power frequency withstand voltage of AC2000V/1min between channel terminals and ground; electrical isolation is implemented between input circuits and backplane bus.
Grouped Power Feeding: The 16 DI channels are split into 2 groups (8 channels per group) with independent reference zero potential for each group.

## II. Hardware Electrical Specifications
### 1. Power Supply Specifications
Module operating power supply: DC24V±20% (fed from redundant 24VDC power supply inside the system cabinet)
Power consumption per base unit: ≤4.8VA
Dielectric Withstand Voltage: Power frequency withstand voltage of AC2000V/1min between channel terminals and ground; galvanic isolation between input circuits and backplane bus
Grouped Power Feeding: 16DI channels split into 2 groups (8 channels per group) with independent reference zero potential for each group

### 2. I/O Terminal Configuration (Matched with DI572 16AC Input Module)
|Interface Category|Parameter Specification|Application Description|
| —- | —- | —- |
|DI Channel Terminals|16-channel AC input wiring terminals (I0~I15), 8 channels per group with separate common terminals for two groups|Connect external AC100~230V passive switch contacts to collect switchgear position change and alarm signals|
|Backplane Bus Interface|AF100/MasterBus300 system backplane slot|DI572 main board is plugged onto the base unit, with bus connection to AC800M controller|
|Power Terminals|DC24V operating power inlet terminals with reverse polarity protection for positive and negative poles|Power sourced from redundant 24V power supply of DCS system|

Input electrical criteria: Logic 0 for input below AC40V; Logic 1 for input above AC79V; power frequency AC sampling at 47~63Hz

### 3. Communication & Status Indication
Bus: MasterBus300 backplane bus, expandable networking via Profibus DP with maximum bus extension of 1200m; built-in bus signal reshaping repeater (DSBC172 integrates bus amplification repeater function)
Indicator Lights: One yellow LED per channel (illuminated when input is conductive) plus separate red/green module indicators for power supply and general fault; local LED alert for channel open-circuit or power loss with remote fault upload via bus
Configuration: Passive wiring on base unit; channel filtering and anti-chatter parameters configurable via DI572 card software (adjustable anti-chatter range: 5ms~200ms)

### 4. Dimension & Environmental Requirements
Overall dimension: 124mm(W) × 72mm(H) × 132mm(D), net weight ≈0.42kg
Ingress Protection: IP20 for cabinet installation
Ambient Temperature & Humidity: Operating: -20℃~+60℃; Storage: -40℃~+85℃; Humidity: 5%~95% RH non-condensing
Certifications: CE, UL; applicable for industrial control of power plants and marine power station environments

## III. Core Functions
1. 16-channel Terminal Distribution: Serves as field wiring base for DI572 module; 16 AC DI channels are split into two isolated wiring groups to separate two independent field power loops and avoid crosstalk or short-circuit faults.
2. S800 Bus Repeater Expansion: Equipped with integrated bus amplification repeater; multiple I/O cards can be mounted on a single base rack to extend DCS rack bus distance and enable automatic redundant bus switching for fault bypass.
3. On-site Channel Fault Diagnosis: LED alarm for single-channel open-circuit or power failure; module fault contacts can be externally wired to SACO16D1 annunciator for centralized fault alarming.
4. Hot-swap Compatibility: Fixed DIN rail for base unit mounting; DI572 module supports hot swapping without unit shutdown to facilitate maintenance during unit operation.

## IV. Complete Matching Solutions
1. Auxiliary Power Monitoring for Power Plant: DSBC172 + DI572 collects feeder protection trip and circuit breaker position signals from REF615, with data transmitted to DCS host system and SACO16D1 alarm panel.
2. Auxiliary Control for Generator Sets: Matched with UNITROL excitation system and REG670 generator protection device to acquire digital signals of cooling fans, oil systems and field suppression breakers.
3. DCS Remote I/O Station: Multiple DSBC172 base units assembled into racks; signal data uploaded to AC800M main controller via Profibus DP to realize remote signal acquisition from local switchgear cabinets.