Product Overview
HIMA F3331 is an 8-channel safety-related digital output module developed by HIMA Paul Hildebrandt GmbH, designed for HIQuad safety control systems. It complies with safety requirement classes AK 1 to AK 6, capable of driving resistive loads, inductive actuators and lamp loads with built-in automatic operational self-test, integrated safety shutdown, safe galvanic isolation and line break monitoring. F3331 features 8 independent output channels with short-circuit resistance and load feedback readback, allowing parallel connection without external diodes. Matched with Z7138/3331 cable plug for standardized field wiring, the 4TE compact form factor saves cabinet installation space. The dedicated software block HB-BLD- supports direct safety logic configuration for F3331 without extra underlying programming, widely deployed in SIS safety interlock systems of process, power and rail industries.
Key Technical Specifications
- Channel output rating: 500 mA per channel, short-circuit proof; max 12 W resistive/inductive load, max 4 W lamp load
- Internal voltage drop: maximum 2 V under full 500 mA load
- Allowable total line resistance (L+ to output): maximum 11 Ohm
- Undervoltage trip point: safety shutdown activated at supply voltage ≤ 16 V DC
- Fault current thresholds: short-circuit current 0.75 A ~ 1.5 A; line break detection current 0.5 mA ~ 9.5 mA
- Leakage & residual voltage: max 350 µA leakage current when output reset; residual voltage ≤ 1.5 V on de-energized channel
- Test signal parameters: maximum test pulse duration 200 µs; 0-signal readback threshold ≤ 6.5 V
- Power consumption: 130 mA at 5 V DC supply; additional 180 mA for 24 V DC load circuits; max 30 mA watchdog input current
- Mechanical dimension: 4 TE rack unit width for standard HIMA IO racks
- Line break monitoring prerequisite: minimum loop load 10 mA; line break diagnostic signal available for safety class up to AK3
- Rack capacity limit: maximum 10 pieces of F3331 per IO rack under full nominal load condition
Certifications: TÜV, CE, SIL 3 safety integrity level, Category 4
Product Core Features
- Continuous automatic runtime self-test with three core test sequences: output signal feedback readback, walking-bit cross-talk & switching capability test, permanent line circuit monitoring
- Galvanic safe isolation between backplane control bus and field load circuits; no output signal generated when L- supply wire breaks to avoid unintended actuation
- Native inductive load compatibility: only external 1N4007 / 1N4448 freewheeling diode required for solenoid valves and contactors
- Standardized cabling system: 8-core / 16-core LiYY cables and 2-pole split wiring plug Z7138/3331, 0.5 mm² wire gauge, 2.8×0.8 mm flat pin plug, standard cable length 750 mm
- Multi-module parallel operation supported, no external diodes needed for capacity expansion of safety interlock points
- Fail-safe hardware logic: all outputs cut off automatically upon detection of short circuit, line break, undervoltage or internal hardware fault
- Channel independent operation: single channel fault will not disrupt the remaining 7 output channels
- Complete software support: HB-BLD- standard function block native to HIMA operating system for rapid diagnostic and logic programming
Application Fields
- Oil & Gas: emergency shutdown valves, flare ignition interlocks, compressor safety trip circuits; F3331 line monitoring detects field cable breakage instantly
- Chemical Process: reactor overpressure relief, toxic gas ventilation interlock, explosion-proof lighting safety control, meets AK6 highest safety standard
- Thermal & Renewable Power: boiler fuel cut-off, turbine trip logic, energy storage fire linkage
- Railway Transit: tunnel fan emergency control, platform screen door safety outputs, train brake interlock circuits
- Machinery Manufacturing: heavy press safety gates, robot emergency stop output loops
Water & Wastewater Treatment: chemical dosing safety cut-off, catalytic incinerator interlock control
Operation Guide
Hardware Installation
- Power off the rack, slide F3331 into the IO slot and lock the module latch; do not exceed 10 F3331 modules per single rack under full load.
- Wire Z7138/3331 plug following color code for L+, L- power and channel 1~8 terminals; mount freewheeling diode across inductive load terminals.
- Verify load power limits: lamp circuits ≤4 W, solenoid circuits ≤12 W, maintain minimum 10 mA loop current for line break monitoring function.
- Restore 24 V DC rack supply, F3331 executes full self-test automatically and enters ready status if no faults detected.
Software Configuration
- Import HB-BLD- function block in HIMA programming software, assign hardware address corresponding to F3331 rack slot.
- Enable diagnostic signals for short circuit, line break and undervoltage alarms; line break signal is applicable for safety class AK1~AK3.
- Configure fail-safe interlock logic for automatic output shutdown upon fault trigger, download project to safety controller to complete commissioning.
Routine Maintenance
- Regularly check diagnostic reports uploaded by F3331 to distinguish four fault types: short circuit, line break, supply undervoltage, internal hardware failure.
- Annual inspection of inductive load freewheeling diodes (part no. 268104004) and matching capacitor (part no. 171112104).
- Clean pin terminals of Z7138/3331 plug to prevent excessive line resistance which triggers false line break alarms; total circuit resistance must stay below 11 Ohm.
Working Principle
F3331 receives output commands from the safety controller via backplane I/O bus, with 8 independent switching circuits driving field loads respectively. Continuous walking-bit self-test runs cyclically during operation, and feedback circuits sample voltage levels on each load channel to judge logic 0/1 state against the 6.5 V threshold.Built-in line monitoring circuits measure loop current constantly: current below 0.5 mA indicates line break, while 0.75 A ~ 1.5 A current range signals output short circuit. The supply voltage monitor tracks L+ rail voltage, activating hardware safety shutdown when voltage drops under 16 V DC.Galvanic isolation separates 5 V control bus and 24 V field load circuits to prevent bus damage from field-side faults. If L- supply wire is disconnected, all output signals are deactivated immediately to eliminate unintended load operation.Freewheeling diodes absorb reverse electromotive force from inductive coils to protect internal switching components; integrated current balancing circuits enable direct parallel connection of multiple F3331 modules without auxiliary external components.
HIMA Output Module Comparison Table
| Comparison Item | F3331 | F3330 | F3322 | F3333 | F3334 |
|---|---|---|---|---|---|
| Channel Quantity | 8 safety outputs | 8 safety outputs | 16 safety outputs | 4 safety outputs | 4 safety outputs |
| Per-channel rated current | 500 mA | 2 A | 500 mA | 500 mA | 2 A |
| Max single channel load | 12 W | 48 W | 12 W | 12 W | 48 W |
| Rack width | 4 TE | 4 TE | 8 TE | 2 TE | 2 TE |
| Line break monitoring | Supported, min 10 mA load | Supported, external resistor required | Supported, min 10 mA load | Supported, min 10 mA load | Supported, external resistor required |
| Typical Use Case | Small solenoids, lamp loads | Heavy-duty contactors, hydraulic valves | Dense small-scale safety systems | Space-restricted cabinets with few channels | High-power single-channel actuators |
Matching Accessories & System Hardware
- Wiring accessories: Z7138/3331 cable plug (8-core / 16-core / 2-pole split), 0.5 mm² LiYY shielded cable, 1N4007 freewheeling diodes
- System hardware: HIMA H41q / H51q safety controllers, F7126 / F7130A rack power supply modules, standard 4TE / 8TE IO mounting racks
- Software tools: HIMA programming & configuration software, HB-BLD- standard function block library
- Monitoring equipment: HIMA upper computer diagnostic software, fault signal data acquisition terminals
Frequently Asked Questions
Q1: What is the maximum load capacity per single channel of F3331?A1: Resistive and inductive loads are limited to 12 W, lamp loads capped at 4 W; overload will trigger overcurrent protection and cut off outputs.
Q2: Why F3331 fails to detect line break faults?A2: Loop current lower than 10 mA disables line break monitoring; add small current-limiting resistors to raise base loop current, and check if total line resistance exceeds 11 Ohm.
Q3: What damage will occur if inductive loads operate without external diodes on F3331?A3: Reverse high voltage generated by de-energized coils will break internal switching circuits and cause permanent hardware failure of F3331; freewheeling diodes are mandatory for all inductive actuators.
Q4: What is the maximum quantity of F3331 modules allowed on one IO rack?A4: Maximum 10 modules under full nominal load; light-load layouts can add extra modules subject to rack power supply capacity.
Q5: Is residual voltage on reset outputs of F3331 normal?A5: Yes, the specification allows maximum 1.5 V residual voltage and 350 µA leakage current on de-energized channels, insufficient to actuate field loads.
Q6: Will the 200 µs maximum test pulse trigger unintended load operation?A6: No, the ultra-short pulse duration cannot energize solenoids or lamps, only used for internal diagnostic verification without field actuation risk.
Q7: Are external diodes required for parallel connection of multiple F3331 modules?A7: No, internal current balance protection circuits support direct parallel operation; only individual inductive load branches need separate freewheeling diodes.
Q8: What is the undervoltage trip threshold of F3331 and how to reset?A8: Safety shutdown activates at supply voltage ≤ 16 V DC; outputs recover automatically after supply voltage restores to standard 24 V DC once self-test completes.
HIMA Safety Output Series Model List
F3322 16 fold safety output moduleF3330 8 fold high-power safety output moduleF3331 8 fold standard safety output moduleF3333 4 fold standard safety output moduleF3334 4 fold high-power safety output moduleF3422 8 fold safety relay output moduleF3430 4 fold safety relay output moduleF9430 24 fold digital input & output moduleF6705 2 fold analog safety output moduleF6706 2 fold high-precision analog output moduleF5220 2 fold counter output moduleF6214 4 fold analog input moduleF6215 8 fold analog input moduleF6220 8 fold thermocouple input module
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