Description
Detailed parameter table
| Parameter name | Parameter value |
| Product model | Metso IOP303 |
| Manufacturer | Metso Outotec Corporation |
| Product category | Ultra-Entry-Level 2-Channel Analog Input Module (for Minimal-Scale Monitoring) |
| Input Signals | Exclusive to 4–20 mA current loops (no 0–10 VDC option); Compatible with basic industrial sensors: pressure transmitters, RTDs (via signal conditioners), level sensors |
| Number of Input Channels | 2 single-ended channels (shared common ground); Channel-to-channel isolation: 50 Vrms (basic noise protection for low-interference environments) |
| Measurement Accuracy | ±0.3% of full scale (FS) at 25 °C; ±0.6% FS over operating temperature range (-5 °C to +50 °C); Resolution: 12 bits (sufficient for standalone monitoring tasks) |
| Communication Interface | Only Modbus RTU (RS-485, fixed 9600 baud, even parity); No adjustable settings (optimized for zero-configuration setup) |
| Physical Dimensions | Ultra-compact DIN rail form factor: 18 mm (width) × 80 mm (height) × 60 mm (depth); Weight: ~150 g; IP Rating: IP20 (panel-mount, dust-protected only) |
| Environmental Requirements | Operating temperature: -5 °C to +50 °C (indoor, climate-controlled spaces only); Storage temperature: -15 °C to +55 °C; Relative humidity: 15%–85% (non-condensing); Vibration resistance: 0.2 g (10 Hz–500 Hz); Shock resistance: 10 g (11 ms half-sine) |
| Power Requirements | 24 VDC (20–28 VDC narrow range, optimized for standard industrial power supplies); Power consumption: < 0.8 W (max, both channels active); No auxiliary sensor power output (requires external 24 VDC supply) |
| Safety & Compliance | CE (EN 61010-1); RoHS 2 compliant (lead-free); No UL certification or hazardous area ratings (for non-critical, low-risk environments only) |
| Compatibility | Works with Metso systems: Metso FieldCare Lite (v2.0+) (basic device recognition only); Compatible with 3rd-party micro-PLCs: Siemens S7-1200 (basic mode), Allen-Bradley Micro810, Schneider M200; Supports 24–18 AWG wire (stranded only) |
| Additional Features | LED indicators (1 power LED: green = on; 2 channel LEDs: green = signal detected, red = overrange); Non-removable terminal blocks (screw-type, small flathead required); Fixed default Modbus address (1, no software reconfiguration); Built-in overcurrent protection (50 mA max per channel) |
METSO IOP303
Product introduction
The Metso IOP303 is an ultra-entry-level 2-channel analog input module developed by Metso Outotec, engineered to fill the gap for minimal-scale analog monitoring—from standalone tank level tracking in small warehouses to single-zone HVAC temperature monitoring in convenience stores. Unlike the 4-channel Metso IOP304 (with optional 0–10 VDC and adjustable baud rate) or higher-tier Metso IOP320 (analog output, IP65), the Metso IOP303 focuses on “just enough” functionality: it converts 4–20 mA signals from two sensors into digital data, transmits via fixed 9600-baud Modbus RTU, and requires almost no configuration—making it ideal for users with no automation experience or tight budgets.
As the most compact model in Metso’s entry-level I/O lineup, the Metso IOP303 excels in scenarios where space and cost are non-negotiable. For example, a small beverage distributor uses the Metso IOP303 to monitor level in two syrup tanks: each channel connects to a 4–20 mA ultrasonic sensor, and the module sends data to an Allen-Bradley Micro810 PLC (fixed 9600 baud). Unlike the Metso IOP304, which has extra channels the distributor doesn’t need, the Metso IOP303 fits in a 50 mm-wide DIN rail slot (shared with a relay) and costs 30% less. Whether used in small retail, local manufacturing, or municipal utility small sites, the Metso IOP303 delivers Metso’s signature reliability in a “right-sized” package for ultra-small monitoring tasks.
Core advantages and technical highlights
18 mm Ultra-Narrow Width for Extreme Space Constraints: The Metso IOP303’s 18 mm DIN rail width is 18% narrower than the Metso IOP304 (22 mm) and 64% narrower than the Metso IOP320 (50 mm)—critical for the tiniest control panels or retrofits where space is a premium. A convenience store’s HVAC technician installs the Metso IOP303 in a 70 mm-wide panel (shared with a thermostat and power supply): its slim profile eliminates the need to replace the panel (a $200 expense if using a wider module). This space efficiency is unmatched by any other Metso I/O module, making the Metso IOP303 the only viable choice for ultra-compact setups.
Zero-Configuration Setup for Non-Technical Users: The Metso IOP303 has fixed Modbus settings (9600 baud, address 1) and no software-adjustable features—users can wire it and start monitoring in 5 minutes. A local bakery owner (with no automation training) sets up the Metso IOP303 to track two oven temperatures: after wiring 4–20 mA RTD transmitters to channels 1 and 2, the module automatically sends data to a Siemens S7-1200 PLC (preconfigured to 9600 baud). Unlike the Metso IOP304, which requires Metso FieldCare Lite to set a Modbus address, the Metso IOP303 needs no software—perfect for users who want to avoid complex setup.
Lowest Cost in Metso’s I/O Lineup for Budget-Conscious Users: The Metso IOP303 is priced 30% lower than the Metso IOP304 and 70% lower than the Metso IOP320—enabling users to add monitoring without overspending. A small water utility uses 4 Metso IOP303 modules (one per small lift station) to monitor pump discharge pressure: the total cost is 40% less than using two Metso IOP304 modules (with unused channels) and integrates seamlessly with Schneider M200 PLCs. This affordability doesn’t sacrifice reliability—Metso’s quality testing ensures the Metso IOP303 operates consistently for 4+ years in indoor environments.
Overcurrent Protection for Sensor Safety: The Metso IOP303 includes 50 mA per-channel overcurrent protection—preventing damage from accidental sensor short circuits (common in small facilities with uncertified wiring). A small manufacturer’s intern accidentally shorts a 4–20 mA pressure sensor to the Metso IOP303: the module’s protection triggers, stopping current flow to the channel instead of damaging the ADC. After fixing the short, the Metso IOP303 resumes normal operation—avoiding a $150 replacement cost (vs. unprotected generic modules). This feature gives non-technical users peace of mind during installation.
Typical application scenarios
In small retail, a clothing store uses the Metso IOP303 to monitor two critical points: warehouse humidity (via a 4–20 mA humidity transmitter) and HVAC supply air temperature (via a 4–20 mA RTD sensor). The module’s 18 mm width fits in a tiny backroom panel (shared with a power strip), and its fixed 9600 baud connects to a Schneider M200 PLC. The PLC sends an alert to the store manager’s phone if humidity exceeds 60% (risking fabric mildew) or temperature drops below 18 °C (risking pipe freeze). The Metso IOP303’s simplicity means the manager (no automation experience) can verify operation via LED indicators—green lights confirm sensors are working, red lights signal issues. This setup costs 50% less than a multi-channel alternative and solves the store’s specific monitoring needs.
In local manufacturing, a custom furniture shop uses the Metso IOP303 to track two glue pot temperatures: each channel connects to a 4–20 mA thermocouple transmitter (powered by an external 24 VDC supply). The module sends data to an Allen-Bradley Micro810 PLC, which displays temperatures on a small HMI. If either pot exceeds 60 °C (glue degradation risk), the PLC triggers a cooling fan. The Metso IOP303’s low power consumption (0.8 W) aligns with the shop’s energy goals, and its non-removable terminals prevent accidental wire disconnection during daily shop activity. Unlike the Metso IOP304, which has extra channels the shop doesn’t use, the Metso IOP303 is a “no-waste” solution that fits the shop’s small-scale production needs.
METSO IOP303
Related model recommendations
Metso IOP304: 4-channel upgrade of the Metso IOP303—adds 2 extra channels, optional 0–10 VDC, and adjustable baud rate—for users scaling to more monitoring points (e.g., 3–4 sensors).
Metso PS-240: 24 VDC, 0.5 A ultra-compact power supply for the Metso IOP303—powers 2 sensors (50 mA each) and the module, fits in 15 mm DIN rail space (matches the module’s compactness).
Metso FieldCare Lite (v2.0+): Software for basic Metso IOP303 verification—detects the module on Modbus, displays channel values, and flags overrange errors (no configuration needed).
Siemens S7-1200 PLC (1211C Basic): Micro-PLC optimized for the Metso IOP303—preconfigurable to 9600 baud, supports 2-channel analog data logging, ideal for small retail/manufacturing.
Allen-Bradley Micro810 PLC: Ultra-compact PLC fully compatible with the Metso IOP303—fixed 9600 baud support, 2 analog input channels (matches the module’s output), costs < $200.
Metso TC-18: 18 mm-wide terminal block cover for the Metso IOP303—protects terminals from dust and accidental contact, fits the module’s narrow profile (no overhang).
Metso IOP331: Digital input complement to the Metso IOP303—8 channels, NPN/PNP auto-detect—for users adding digital sensors (e.g., limit switches) alongside 2 analog points.
Schneider M200 PLC: Budget micro-PLC for the Metso IOP303—fixed 9600 baud Modbus RTU, simple HMI integration, suitable for municipal small sites (e.g., lift stations).
Installation, commissioning and maintenance instructions
Installation preparation
Before installing the Metso IOP303, power off the control system and wear ESD wristbands to protect the module’s 12-bit ADC. Verify the module’s power supply (20–28 VDC) matches the external 24 VDC source—do not use voltages outside this range (unlike the Metso IOP304’s wider 18–30 VDC). Mount the Metso IOP303 on a standard 35 mm DIN rail—ensure 3 mm clearance on both sides (sufficient for airflow, given its low 0.8 W consumption) and avoid installing near heat sources (e.g., heaters).
Wiring requires a small flathead screwdriver (terminals are non-removable): strip 4 mm of insulation from 24–18 AWG stranded wire (solid wire not recommended), insert into terminals (labeled: V+, GND, CH1, CH2, A, B), and tighten screws to 0.15 N·m (over-tightening breaks terminals). Connect sensors to CH1/CH2 (ensure polarity: + to CHx+, – to GND). Connect RS-485 A/B lines to the PLC’s Modbus port—use 0.5 mm² twisted-pair cable (max run: 50 meters, shorter than the Metso IOP304’s 100 meters, due to lower isolation).
Commissioning and maintenance
Power on the system and verify the Metso IOP303’s power LED turns green (no power = check wiring or supply). Check channel LEDs: green = sensor connected and sending 4–20 mA; red = overrange (>20 mA) or short circuit. Use a multimeter to confirm sensor signals (e.g., 4 mA = empty tank, 20 mA = full tank) at the module’s terminals—no software needed for verification.
For maintenance, inspect the Metso IOP303 every 6 months: wipe dust from the housing with a dry cloth (IP20 防尘 only), check terminal screws for tightness (loose wires cause intermittent green LEDs), and verify power supply voltage (24 VDC ±5%). If a channel shows red LED, disconnect the sensor and test with a 4–20 mA signal generator—if green LED returns, replace the sensor; if not, replace the entire module (no field-repairable parts). Store spares in a dry cabinet (avoid -5 °C below or +50 °C above—colder/hotter than the Metso IOP304’s range).
Service and guarantee commitment
Metso provides a 9-month standard warranty for the Metso IOP303, covering defects in materials, workmanship, and performance (e.g., channel failure, no communication). During warranty, Metso replaces the module free of charge if it fails under normal indoor use (proof of purchase required—simplified receipt accepted, no formal documentation). No extended service plans are available, aligning with its ultra-entry-level positioning.
Metso’s technical support for the Metso IOP303 is simplified: available via online chat (12-hour response time, business days) and a dedicated FAQ page (step-by-step wiring guides, LED error troubleshooting). No email or phone support (reserved for higher modules like the Metso IOP304). Support focuses on common issues: “red LED fixes,” PLC baud rate matching, and sensor polarity checks—tailored to non-technical users.
For out-of-warranty issues, Metso offers a 20% discount on a new Metso IOP303 (valid 4 months after failure—shorter than the Metso IOP304’s 6 months, due to lower cost). Customers get free access to a 1-page “Quick Start Guide” (wiring diagram + LED meanings) and a 2-minute installation video—no complex resources. This commitment balances affordability with practical support, ensuring ultra-small-scale users get the help they need without extra costs.
