Model Code Definition

DKR = DIAX02 high-current single spindle driver family

02 = 2nd generation DIAX hardware platform

.1 = Hardware revision Release 1

W = Integral axial fan forced convection cooling

300 = Continuous rated output current 300Arms

N = No built-in internal brake bleeder chopper（external brake resistor required）

BT = Basic SERCOS CNC control mainboard series（economical base version, less IO & feedback than BE series）

26 = Entry-level SERCOS control card: single feedback channel, fixed minimal onboard IO, no expandable slot reserve, basic speed/position closed-loop only, no C-axis & electronic gear function

01 = First standard PCB hardware layout

-FW = Pre-installed DSM card with preloaded ESM02.3 official factory firmware, unit ready-to-run out of box

Technical Specifications

Main Power Input：3Φ AC400~480V ±10%, 50/60Hz; isolated 24VDC auxiliary control power supply

DC Bus Nominal Voltage：700VDC

Output Rating：Continuous 300A RMS; 250% overload sustain 300ms, 300% instantaneous peak overload; max output frequency 1200Hz, matching max spindle rated power ~93kW; carrier frequency optional 4kHz(full rating)/8kHz(output derate to 110A)

Braking Setup：N-type no internal bleeder, all regenerative energy consumed via external braking resistor

Cooling：Built-in blower forced air cooling, total power loss ~1820W

Protection Class：IP20 per IEC standard, cabinet vertical installation only

Ambient Operating：0~+45℃ full-load, automatic current derate over 45℃; storage -30~+85℃; working altitude ≤1000m; relative humidity＜90% non-condensing

Dimension & Net Weight：H1065×W468×D392mm, net weight ≈60.5kg

Interface & Communication Configuration

Power Terminals：Heavy-duty L1/L2/L3 mains input terminals, U/V/W high-current motor output terminals

SERCOS Bus：Standard fiber-optic SERCOS real-time bus for CNC speed/position command transmission

Feedback Port：Single 15Pin D-SUB feedback socket, support either resolver OR TTL incremental encoder single-channel feedback only（no dual/triple feedback like BE series）

Onboard IO：Fixed minimal 8DI/5DO digital IO, U2/U3/U4 base slots vacant without expansion reserve

Debug Port：Front panel RS232 serial port for IndraWorks parameter tuning, fault diagnosis

Auxiliary Terminal Block：Drive enable, hardware E-stop, motor PTC thermal protection, fault relay dry contact, drive ready status terminals

FW Module：Front slot factory fitted DSM card with preloaded ESM02.3 firmware（-FW marked model）, no empty card slot

Core Functions

Standard three-loop（torque-speed-position）closed-loop spindle control; BT26 core limitation vs BE variants: no C-axis continuous indexing, no electronic gear synchronization, single feedback exclusive selection without dual-switch function, no rigid tapping support; complete hardware protection including overcurrent, DC bus over/undervoltage, power module overheat, fan failure, feedback breakage, front digital LED fault code display; -FW version directly powers up after wiring without extra firmware programming.

Application Fields

Ordinary vertical machining center main spindle without C-axis function, general printing equipment main drive, common metallurgy unwinding/rewinding spindle, retrofitting of old conventional NC machine spindle requiring basic SERCOS communication.

Operation & Maintenance Instructions

Only connect three-phase AC400~480V industrial mains; single-phase input triggers DC bus undervoltage lockout and no output.

Reserve ≥100mm top & bottom ventilation clearance inside control cabinet to guarantee fan airflow and avoid overheat shutdown or power derating.

N-type no internal brake chopper: configure matched external braking resistor under frequent start-stop or emergency stop working condition to prevent DC bus overvoltage alarm.

BT26 mainboard hardware incompatible with BE11/BE37/BE56/BE79 control boards, cannot cross-replace during maintenance repair.

-FW suffix unit retains factory original ESM02.3 firmware; firmware update requires dedicated BT26 DSM memory card via IndraWorks offline flashing.