The Sorensen MML-2 is a 4U, two-bay programmable DC electronic load mainframe designed for versatile bench-top or rack-mount environments. Each bay accepts a plug-in load module, providing up to 1.2 kW of total sink capacity when both bays are populated with 600 W modules. Front-panel push-button and keypad controls allow local setup and operation, while RS-232C comes standard for remote control; an optional IEEE-488.2 (GPIB) interface supports full SCPI-style command sets. Built-in self-test on power-up, remote sense inputs, and analog Go/No-Go status outputs ensure reliable, repeatable performance in engineering and manufacturing test applications.

MML-80V-120A-601 Module Specifications

• Power and Voltage
  • Maximum power: 600 W
  • Maximum voltage: 0–80 V DC
  • Maximum current: 0–120 A
• Operating Modes
  • Constant Current (CC), Constant Voltage (CV), Constant Resistance (CR)
  • Programmable slew rates up to 5 A/μs
  • Continuous or pulsed loading up to 20 kHz
  • Short-circuit simulation with programmable duration
• Measurement and Control
  • 15-bit A/D resolution for voltage and current readback
  • Two current ranges (0–12 A and 0–120 A) selectable per channel
  • Up to 10 programs and 10 sequences per program stored in module memory
  • Synchronization across modules for parallel or multi-stage testing
• Protection Features
  • Overcurrent (OCP), Overvoltage (OVP), Overpower (OPP)
  • Overtemperature (OTP) and reverse-polarity protection
  • Front-panel indicator LEDs and status registers report fault conditions

Firmware Revision 3.16 Details

Firmware 3.16 resides on the MML-80V-120A-601 module’s onboard microcontroller, managing control algorithms, calibration data, and communication protocols. Key enhancements in this revision include:

• Improved Transient Response
  • Optimized slew-rate control reduces overshoot during rapid current steps
  • Enhanced digital filtering for more stable CV/CC transitions
• Expanded Command Set and Diagnostics
  • New SCPI query :MEAS:CURR:OFFSET? to read internal zero-offset compensation
  • Extended status byte definitions for more granular fault reporting (e.g., OTP sub-codes)
• Calibration and Memory Management
  • Non-volatile storage of per-module calibration coefficients with integrity checks
  • Auto-recalibration routine accessible via :CAL:START command
• Compatibility and Stability
  • Ensures seamless operation with MML-2 mainframes at hardware revision B and later
  • Resolved rare RS-232 framing errors under heavy command traffic