Description
Technical Specifications
| Parameter Name | Parameter Value |
|---|---|
| Product Model | 2MLF-DC8A |
| Manufacturer | Honeywell |
| Product Type | 8-Channel Analog Current Output Module |
| System Series | Honeywell MasterLogic-200 (ML200) PLC I/O |
| Output Channels | 8 independent current output channels |
| Output Signal | DC 4–20 mA (default) / DC 0–20 mA (software-selectable per channel) |
| Load Resistance | ≤ 550 Ω (at 24 V supply) |
| Output Accuracy | ±0.2% FS at 25 °C; ±0.3% over full operating temperature |
| Resolution | 1/16000 step (effective 16-bit, 1.0 µA per step for 4–20 mA) |
| Conversion Speed | 250 µs per channel |
| Isolation | Opto-coupler isolation, output terminals to PLC power rail (no isolation between channels) |
| Terminal Type | 18-point terminal block |
| Current Consumption | 5 V DC @ 190 mA; 24 V DC @ 300 mA |
| Mounting | Single-slot plug-in to MasterLogic-200 I/O rack |
| Weight | 150 g |
| Operating Temperature | 0 °C to +55 °C |
| Storage Temperature | –40 °C to +85 °C |
| Humidity | 5% to 95% RH, non-condensing |
| Certifications | CE, TÜV, UL508, CSA |
| I/O Points Occupied | Changeable type: 16 points; Fixed type: 64 points |
Main Features and Advantages
Per-channel software-configurable output range
Unlike modules that rely on hardware jumpers or DIP switches, the Honeywell 2MLF-DC8A allows each of its eight channels to be independently configured through MasterLogic programming software or system parameters. A single module can therefore drive a 4–20 mA modulating valve on channel 1 and deliver a 0–20 mA speed command to a variable frequency drive on channel 2, without any physical reconfiguration. This flexibility makes the Honeywell 2MLF-DC8A exceptionally well suited to panels where different final elements demand different signal conventions.
High-precision D/A conversion for smooth control
The Honeywell 2MLF-DC8A employs a high-resolution digital-to-analog conversion engine that transforms CPU-generated digital control words into smooth, accurate current signals. With an effective 16-bit resolution (1/16000 step size, equivalent to 1.0 µA per step on the 4–20 mA range) and ±0.2% full-scale accuracy at 25 °C, the module provides the fine granularity required for precise actuator positioning. A conversion speed of 250 µs per channel ensures that output updates keep pace with fast control loops, while the ±0.3% accuracy rating across the full operating temperature range guarantees stable long-term control even in thermally demanding environments.
550 Ω drive capability for long cable runs
Powered from the 24 V backplane supply, the Honeywell 2MLF-DC8A supports a maximum load resistance of 550 Ω. This is sufficient to drive valve positioners and I/P converters located several hundred metres from the control cabinet without signal degradation, making the module a practical choice for large plants such as power stations, cement works, and petrochemical facilities.
Channel-to-backplane isolation
The output terminals of the Honeywell 2MLF-DC8A are galvanically isolated from the PLC power rail by opto-couplers, suppressing ground-loop currents and protecting the CPU and backplane from field-side electrical disturbances. This isolation is a key factor in the module’s reputation for reliability in electrically noisy industrial environments.
Backplane-powered, single-slot installation
Drawing both 5 V logic power (190 mA) and 24 V drive power (300 mA) from the rack backplane, the Honeywell 2MLF-DC8A requires no external power wiring. Its single-slot, plug-in form factor and 150 g weight simplify cabinet layout, while the 18-point terminal block supports straightforward field wiring. The module’s compatibility with standard ML200 CPU and I/O rack configurations ensures seamless integration with both new and legacy MasterLogic-200 systems.
