B&R X20DO8322

Core Technical Specifications

• Output Channel Quantity: 8 independent digital sourcing output channels
• Output Voltage Rating: 24 VDC nominal (18–30 VDC allowable range)
• Per Channel Rated Load Current: 0.5 A continuous
• On-State Channel Resistance Rds(on): 210 mΩ
• Short-Circuit Protection: Per-channel independent thermal shutdown, peak short-circuit current limited below 12A
• Inductive Load Suppression: Internal freewheeling diode integrated for inductive coil flyback voltage absorption
• Switching Delay: Turn-on <300μs, Turn-off <300μs
• Max Resistive Load Switching Frequency: 500 Hz
• Off-State Leakage Current: ≤5μA per channel
• Channel-Bus Isolation Voltage: 500 VAC galvanic isolation
• Operating Temperature: -20°C ~ +60°C, IP20 cabinet installation
• Module Width: 24mm, net weight 68g

Functional Features

1. 8-channel independent sourcing output, single-wire wiring mode simplify field solenoid valve wiring layout
2. Per-channel independent short-circuit thermal protection; automatically shut down faulty channel without affecting other 7 normal output channels
3. Built-in freewheeling diode for inductive loads (relay, solenoid valve), eliminate high flyback voltage damage internal circuit
4. 10ms delay channel overload diagnosis, real-time upload overcurrent fault signal to X20 CPU
5. Front panel independent LED indicator for each channel: output ON state, short-circuit overload fault alarm
6. Compatible X20TB12 12-pin spring plug terminal blocks, rapid field wiring without screwdriver
7. 500V isolation between field load circuit and X-Bus backplane bus, avoid field load short-circuit damage CPU base station
8. High switching frequency up to 500Hz, suitable for high-speed pulse-controlled small solenoid valves

Working Principle

1. X20 CPU transmits digital output on/off command via X-Bus high-speed backplane bus to X20DO8322 module internal logic chip.
2. Logic chip drives each channel MOSFET sourcing switch tube to turn on/off; 24VDC positive voltage output to connected load device, load negative pole connected to cabinet common ground.
3. Internal current sampling circuit real-time monitor each channel output current; if current exceeds overload threshold trigger thermal shutdown protection circuit, cut off single channel output and light fault LED indicator.
4. Integrated freewheeling diode parallel on each output channel; absorb reverse flyback voltage generated when inductive load power off to protect MOSFET switch tube from breakdown damage.
5. Galvanic isolation transformer separate field load circuit and internal bus circuit; field short-circuit fault cannot conduct interference to X20 CPU control bus.

Structure & Material Composition

• Outer Shell: Gray flame retardant PA66 plastic narrow module housing, integrated X20 backplane locking buckle
• Main PCB: Miniature high-density FR4 circuit board, independent MOSFET switch and sampling circuit per channel
• Terminal Interface: Spring quick plug socket matching X20TB12 removable 12-pin terminal block
• Indicator Area: Front panel 8 independent SMD LED lights corresponding to each output channel working state

Installation Requirements

1. Plug into B&R X20 series DIN rail backplane base station, 24mm narrow width compact layout with other X20 I/O modules
2. Field output wiring use 0.5–1.5mm² copper stranded wire, single-wire sourcing connection mode, all load negative terminals unified cabinet grounding
3. Do not connect load current over 0.5A per single channel; use external intermediate relay for high-current actuator expansion control
4. Separate digital output wiring from analog sensor signal trunking to eliminate switching electromagnetic interference
5. Cabinet ventilation gap ≥15mm above module, cooling fan required if cabinet temperature continuously above 50°C

Application Scenarios

Operation & Maintenance Precautions

1. Live hot plug of module forbidden; cut off X20 base station 24V bus power supply before module replacement or wiring modification
2. Inductive load (solenoid valve, relay) cannot cancel internal freewheeling protection by external circuit modification
3. If single channel frequent overload shutdown, check load coil short circuit or wiring ground leakage first
4. Do not connect AC 220V load directly to module output channel; overvoltage will burn all channel MOSFET tubes
5. Regularly clean terminal block dust accumulation every 6 months; dust short-circuit easily triggers channel thermal protection