Product Core Brief

• Model: DLM02, part number 0338434M, V3 hardware version
• Brand: ABB Hartmann & Braun
• Series: Freelance 2000 legacy DCS mixed digital I/O link module, upgraded redundant power variant of DLM01
• Core Function: Collect 8-channel 24VDC discrete sensor feedback and drive 8-channel 24VDC actuator loads; dual independent 24VDC power supply inputs enable cabinet redundant power architecture for high-availability process units
• Product Type: Compact slide-in I/O module, compatible with TU810 / TU814 screw terminal MTU base units
• Key Specs: 8 digital input + 8 digital output combined channels | Dual redundant 24VDC module power supply | Dual isolated groups (4DI+4DO per group) | Universal sink/source 24VDC signal | 500VAC group-to-backplane isolation | Hot-swap certified | Software adjustable input debounceNote: Discontinued high-availability Freelance 2000 DCS legacy I/O hardware, stocked inventory is New Surplus with intact factory anti-static sealed packaging.

Key Technical Specifications

• Module operating supply: Dual redundant 24VDC ±20% power input channels, automatic failover between two power feeds, typical total power dissipation 1.6W

Digital Input Section (8CH)

• Nominal signal: 24VDC universal sink/source
• Logic threshold (EN 61131-2 Type 1): Logic 0 <5V; Logic 1 >15V
• Single-channel input current: 3.5mA @24VDC
• Software debounce filter: 2 / 4 / 8 / 16ms selectable via Freelance engineering software

Digital Output Section (8CH)

• Output topology: Sinking transistor driver
• Rated load: Max 0.5A per channel @24VDC inductive/resistive loads
• Built-in flyback suppression diode for solenoid coils
• Per-channel self-resetting PTC overcurrent foldback protection

Isolation & Protection

• Two independent galvanically isolated groups (Group 1:4DI+4DO; Group 2:4DI+4DO)
• Dielectric isolation: 500VAC between each group and backplane bus
• Per-channel reverse voltage blocking, 600V TVS surge clamping for EMI noise suppression
• Dual power feed reverse polarity and cross-feed short circuit protection

Diagnostics & Mechanical

• Front panel indicators: Individual yellow DI/DO channel status LEDs, green RUN power LED, dual red power fault LEDs for each supply feed, group fault alarm LEDs
• Hot-swap support: Fully hot-swappable on energized Freelance 2000 I/O racks
• Operating temperature: −25°C ~ +60°C full rated load; storage −40°C ~ +70°C, non-condensing humidity 5%–95%
• Dimensions: W45 × H102 × D119 mm; unit mass 0.16kg
• Mounting: TS35 DIN rail via TU810 / TU814 terminal base assemblies
• Compliance: CE, UL, RoHS, IEC 61000-6-2 Class A industrial EMC, EN 61010 safety standard
• System compatibility: ABB Freelance 2000 DCS local and remote fieldbus I/O stations; incompatible with S800 AC800M, Mod300 S100, AC500 S500 platforms

Product Introduction

is the redundant power upgraded version of DLM01 mixed digital I/O link module for ABB Freelance 2000 DCS high-availability process cabinets. It consolidates 8-point discrete input sensing and 8-point actuator drive output into one rack slot while adding dual independent 24VDC power supply inputs with automatic seamless failover, eliminating single power feed failure risk for safety-critical loops in power, chemical and offshore plants.Dual isolated channel groups limit fault spread: a shorted field cable only disables a 4-channel subgroup instead of all 16 I/O points. Universal sink/source input wiring adapts to different plant sensor wiring standards, integrated surge/overcurrent protection removes external signal conditioning hardware, and hot-swap replacement reduces unplanned process downtime without full rack power shutdown.

QA & Testing SOP (Transparency Building)

1. Incoming Inspection: Cross-reference serial numbers against ABB Freelance 2000 legacy component trace databases; inspect rear gold edge connector pins for oxidation, front dual power fault LED segment integrity, PCB conformal coating for peeling; verify factory static packaging seal remains unbroken for surplus stock.
2. Live Testing: Mate the unit to a TU810 terminal base on a DIN rail test bench paired with a Freelance controller simulator, dual independent 24VDC power supplies, dry contact signal generators and 0.5A solenoid load banks; simulate single power feed loss to verify automatic power failover without I/O state loss; run uninterrupted 24-hour cyclic DI state polling and DO on/off switching across all debounce timing settings; use a Fluke 115 to log steady dual-channel 24VDC supply voltage through the full test cycle.
3. Electrical Testing: Perform 500VAC hipot insulation testing between each 4+4 isolated group and Freelance backplane logic ground; pass threshold set at >10MΩ insulation resistance; inject reversed 24VDC power feed, short-circuit field and cross-feed faults to confirm hardware protection activates without damaging input optocouplers, output transistors or power switch semiconductors.
4. Firmware/Config Backup: Record factory module interface firmware revision via Freelance engineering software; photograph TU81x terminal pin layouts for dual power feed wiring and document factory default debounce filter and fail-safe output values for field commissioning reference.
5. Final QC & Packaging: Torque all TU81x base terminal screw connections to OEM torque specifications; enclose the board in static-dissipative foam; attach a printed QC tag listing serial number and completed test metrics before carton sealing.

Installation Pitfalls & Guide (Engineer to Engineer)

❗Freelance Controller Firmware Mismatch Risk: Outdated Freelance CPU firmware lacks calibrated dual power fault register, debounce register and group fault register mapping for the module. Fault outcome: Missing power supply loss HMI alarms, unfiltered contact bounce generating false discrete status alarms, delayed safety interlock response during process load transients. Mitigation: Flash matching validated firmware revisions to the Freelance controller before rack power-up; archive compatible firmware files to plant engineering servers.❗Single Power Feed Only Wiring Risk: Connecting only one 24VDC supply feed leaves no redundant backup; power feed loss triggers full module shutdown and loss of all 16 I/O points. Fault outcome: Complete safety interlock outage during single power supply failure. Mitigation: Wire both independent module power terminals to separate isolated 24VDC power distribution circuits per TU terminal wiring schematic.❗Excessive DO Load Current Risk: Connecting solenoids drawing more than 0.5A per channel triggers continuous PTC foldback cycling. Fault outcome: Rapid flickering valve states and persistent module fault HMI alarms. Mitigation: Install intermediate auxiliary relays for loads exceeding the single-channel current rating.❗Terminal Base Incompatibility Risk: Attempting to mount the module to non-TU810 / TU814 series base units creates misaligned edge connector pinouts and unregulated field voltage exposure. Fault outcome: Burned DI/DO circuit and power switch semiconductors, permanent module failure. Mitigation: Only deploy the unit paired with OEM TU810 or TU814 terminal base assemblies.❗Cross-Group Common Wiring Error: Jumping negative return lines across separate isolated 4+4 channel groups breaks group galvanic separation performance. Fault outcome: Cross-group signal bleed generating unintended simultaneous solenoid energization and fluttering sensor status readings during motor contactor switching transients. Mitigation: Maintain isolated negative return wiring for each independent group per the TU terminal wiring schematic.❗ESD Dangers: Low-humidity refinery and offshore control room air generates static charge that damages delicate input optocoupler, output transistor and power switch ICs on the PCB. Field service logs show ungrounded handling creates intermittent stuck-on actuator, flickering sensor and false power fault alarms that require multiple interlock diagnostic shifts to isolate. Mitigation: Establish direct contact with bare cabinet chassis ground metal for three full seconds before touching module edge connectors or base terminal blocks.

4-Step Replacement Guide

1. Pre-install: Set the Freelance 2000 controller to manual hold mode to lock all discrete interlock logic states; photograph all limit switch, solenoid valve and dual redundant power feed wiring assignments on the TU81x terminal base assembly, and record current debounce filter and fail-safe output parameter settings in Freelance engineering software.
2. Removal: Slide the module straight upward out of the TU81x base without bending edge connector pins; leave all field and dual power wiring terminated to the base to eliminate full retermination labor.
3. Install: Align the new unit’s rear edge connector with the TU81x base slot and slide fully seated until the module retention tab locks into place; replicate dual redundant power wiring, debounce timing, overcurrent fault monitoring and fail-safe output parameter configurations within Freelance engineering software to match original high-availability process requirements.
4. Power-on Test: Energize both independent 24VDC power supply feeds; simulate single power feed loss to verify seamless automatic power failover without I/O state dropout; toggle simulated open/closed sink/source contact signals to all 8 DI channels and cycle on/off commands to all 8 DO channels via the controller simulator, confirm consistent discrete state reporting and stable solenoid actuation with zero power/group fault flags accumulating during 30 minutes of idle loop testing before restoring live process control logic.

FAQ (Frequently Asked Questions)

Q: What is the core hardware difference between and DLM01?A: DLM01 has single 24VDC module power input with no power redundancy; adds dual independent 24VDC redundant power supply feeds with automatic failover and dual power fault diagnostic LEDs, all DI/DO channel, isolation and debounce specifications are identical.Q: Can directly replace DLM01 without full DCS point rework?A: Mechanical swap to same TU base is fully compatible, all discrete point addresses and channel logic remain unchanged. The only extra work is wiring the second redundant 24VDC power feed and configuring dual power fault alarm registers in Freelance engineering software.Q: Does hot-swap eliminate the need for manual hold mode before replacement?A: Hot-swap only protects internal module semiconductors from power transients; it cannot maintain DI readings or hold DO output states during the swap window. Manual hold mode must still be enabled on the Freelance controller to avoid unplanned valve/pump actuation and safety interlock trips.Q: What warranty applies to surplus stocked units?A: A 12-month limited warranty only covers factory manufacturing defects. Damage from single-feed power wiring architecture, overcurrent DO loads, ungrounded ESD handling, incompatible TU terminal bases, sustained field wiring short-circuits or firmware mismatch faults is excluded from warranty claims.Q: If one DI or DO channel inside an isolated group fails, can individual IC components be repaired on-site?A: Field repair of damaged input/output/power circuits is not recommended for critical safety interlock systems. Repaired PCB traces degrade group isolation and redundant power switch performance and raise risk of unintended actuator energization or false safety trips; full module swap is the standard site maintenance procedure.Q: Can multiple units share dual redundant 24VDC field power circuits in one Freelance rack?A: Multiple units may share two separate redundant 24VDC supply buses only if each supply maintains 20% extra current headroom above total combined module power draw. Independent auxiliary feed wiring is recommended for racks with six or more modules to eliminate voltage sag during simultaneous high-frequency I/O switching events.Q: Is rated for Class 1 Div 2 hazardous cabinet deployment inside refinery pump MCC rooms?A: No, the open slide-in module + TU base design lacks intrinsic safety certification for flammable vapor environments. Flameproof dedicated Freelance I/O enclosures are required for hazardous area process installations.Q: What long-term hardware upgrade path exists as reaches end-of-support?A: Modern ABB high-availability process control deployments use System 800xA S800 DI810 + DO810 separate I/O modules paired with dual redundant cabinet power distribution to replace legacy Freelance 2000 hardware. Full Freelance rack migration, field and power wiring rework, and complete discrete channel parameter reconfiguration in Control Builder M are required for a direct functional retrofit.