Product Overview
The Honeywell 942-M0A-2D-1G1-220S is a 942 Series ultrasonic proximity and distance sensor from Honeywell’s position-sensing portfolio, built on the series’ distinctive separate “evaluation box” architecture rather than the self-contained barrel-sensor form factor. The 942-M0A-2D-1G1-220S pairs a remote stainless-steel M30 ultrasonic sensor head — which can be mounted on a tank roof, inside a machine, or in any location that is difficult to access — with a dedicated control unit that carries every adjustment and output termination. This split design is the defining advantage of the model: the head never touches the product being measured, while the control box sits in a cabinet on a DIN rail where it can be adjusted without dismantling equipment.
The Honeywell 942-M0A-2D-1G1-220S operates at an ultrasonic frequency of 220 kHz and covers a measurement range of 150 mm to 1500 mm (6.0 to 59.0 in), placing it in the mid-range class of the 942 family. It converts the time-of-flight of the reflected sound pulse into two simultaneous analog signals — 0–10 V DC and 4–20 mA — and provides two independently programmable PNP switching outputs with selectable setpoints and NO/NC behavior. An RS-232 serial link allows PC-based configuration and diagnostics through the Windows-compatible software supplied for the 942 series.
Built-in temperature compensation is a key feature of the 942-M0A-2D-1G1-220S: because the speed of sound in air changes with temperature, an uncompensated ultrasonic sensor drifts for reasons unrelated to the actual distance being measured. The sensor corrects for this automatically, preserving repeatability of ±0.2 % ±1.0 mm and linearity of 0.3 % ±2.0 mm across the measuring range. A synchronizing/hold input allows multiple sensors to fire in sequence rather than hearing each other’s pulses, preventing cross-talk in multi-sensor installations. Basic setup is performed on front-panel coding wheels and switches; deeper parameters such as hysteresis, DSP filtering, and analog slope are handled over the serial link.
Technical Specifications
| Parameter Name | Parameter Value |
|---|---|
| Product Model | Honeywell 942-M0A-2D-1G1-220S |
| Manufacturer | Honeywell (Sensing & Productivity Solutions / Sensing and Control) |
| Product Type | 942 Series ultrasonic proximity / distance sensor — separate evaluation and control unit |
| Architecture | Split design: remote sensor head + DIN-rail control/evaluation box |
| Compatible Heads | 942 and 947 series ultrasonic sensor heads (kit reference 942-A4M-2D-K220S) |
| Sensing Range | 150 mm to 1500 mm (6.0 in to 59.0 in) |
| Range Class | Mid range: 1.0 m to 2.0 m |
| Operating Frequency | 220 kHz |
| Supply Voltage | 19 V DC to 30 V DC (24 V DC nominal) |
| Current Consumption | 50 mA maximum |
| Repeatability | ±0.2 % ±1.0 mm |
| Linearity | 0.3 % ±2.0 mm |
| Analog Outputs | 0–10 V DC (load >1.45 kΩ) and 4–20 mA (load <250 Ω), simultaneous |
| Switching Outputs | 2 × PNP open collector (setpoints SP1 and SP2), NO/NC selectable |
| Maximum Output Current | 100 mA |
| Serial Interface | RS-232, 3-wire |
| Memory | EEPROM (non-volatile) |
| Hysteresis | Programmable by software (default 1 %) |
| Sensitivity Adjustment | Switchable (33 % or 100 % beam power) |
| Temperature Compensation | Built-in, automatic |
| Additional Indicators | 5 LEDs |
| Additional Inputs | Overrange, underrange, parallel outputs, Hold/Synchronize |
| Response Time | 60 ms (target moving <1 m/s); 300 ms (target presence/absence) |
| Maximum Switching Frequency | 8 Hz |
| Protection | Reverse polarity, voltage-spike, and short-circuit protection on switching outputs |
| Control-Box Enclosure | Plastic with screw terminals, IP40 |
| Mounting | DIN rail or two-hole (Ø 4 mm) panel mounting |
| Sensor Head | Stainless-steel M30, IP65 |
| Operating Temperature | 0 °C to +50 °C (control box) |
| Storage Temperature | −25 °C to +85 °C |
| Approvals | CE, UL, CSA |
| Weight (approx.) | 0.32 kg |