Key Technical Specifications
| Parameter | Value |
|---|---|
| Model | 567LH-DP24 |
| Manufacturer | REOTRON |
| Product Type | Output Logic Module / Analog Voltage Source |
| Channel Count | 8 points, isolated |
| Output Type | Analog voltage |
| Alarm Functions | Out-of-range (±50mV threshold), user power loss, uncalibrated module |
| Alarm Reporting | Alarm bits set in discrete input data; clearable via discrete output command |
| Application Domain | Industrial automation, servo control, process output |
| Mounting | Module form factor (verify with cabinet/backplane specs) |
| Calibration | Factory calibrated; recalibration may be required after replacement |
Product Introduction
I’ve dealt with enough analog output modules to know that the ones causing the most headaches aren’t the ones that fail outright — they’re the ones drifting silently, feeding 4.8mA when the system expects 5.0mA, and nobody notices until a valve is half-open when it should be fully closed. The REOTRON 567LH-DP24 is an 8-point isolated analog voltage output module. It sits between your controller and the field devices, converting engineering unit values from the host into precise voltage signals that drive actuators, servo systems, and process equipment.What makes this module worth paying attention to is its built-in alarm architecture. It reports three distinct fault conditions — out-of-range output (triggered when the host commands a value roughly 50mV beyond the module’s physical limits), user power loss, and an uncalibrated state. These alarm bits are written into the module’s discrete input data word, where your application logic can monitor them. That’s a useful feature because it means you can catch a failing output channel before it causes a process upset, rather than discovering the problem when something downstream stops moving. The isolation between channels also matters in noisy industrial environments where ground loops can corrupt analog signals.
Quality SOP & Tech Pitfalls
The Lab Report (SOP)
Before this module ships, the following checks should be performed:
- Visual/Counterfeit Inspection: Verify REOTRON markings, check for rework signs, confirm part number 567LH-DP24 is clearly legible on the module label.
- Physical Inspection: Examine connectors for bent pins, check the module housing for cracks or heat damage, verify all terminal connections are intact.
- Channel Output Test: Using a calibrated multimeter or process calibrator, command each of the 8 channels to known output values and verify the actual voltage matches within specification tolerance.
- Alarm Function Test: Deliberately trigger each alarm condition (out-of-range command, power removal, uncalibrated state) and confirm the corresponding alarm bit is set in the discrete input data.
- Isolation Verification: Measure insulation resistance between channels and between channels and ground to confirm isolation integrity.
- Anti-static Packaging: Seal in ESD-safe packaging for shipment.
The Engineer’s Warning (Pitfalls)
- Skipping the calibration check after replacement. If you swap in a replacement 567LH-DP24 without verifying its calibration against your process requirements, you’re flying blind. An uncalibrated module will report itself as such via the alarm bit — but if your logic doesn’t monitor that bit, you’ll never know. I’ve seen entire batches of analog outputs run for months with a 3% offset because nobody checked the alarm word.
- Ignoring the 50mV out-of-range threshold. If your host application occasionally commands values near the module’s physical limits, you’ll get intermittent out-of-range alarms. That’s not a module fault — it’s a scaling problem in your logic. Fix the scaling, don’t just mask the alarm.
Installation & Configuration Guide
- Pre-Installation (⚠️ Safety First)
- Isolate power to the controller rack and field wiring connected to the output channels.
- Photograph the existing module’s position, orientation, and all wiring connections. Label each wire with its channel number and destination.
- Note the current alarm configuration in your application logic — you’ll need to replicate it on the replacement.
- Removal
- Disconnect all field wiring from the module’s output terminals.
- Release the module from its mounting position (DIN rail, backplane slot, or panel mount — verify your specific installation).
- Handle the removed module with ESD precautions.
- Installation
- Before inserting the new 567LH-DP24, verify that all 8 channel terminals are clean and undamaged.
- Seat the module in the same position as the original.
- Reconnect field wiring to the correct channel terminals per your labels and photographs.
- Reconnect any grounding or shielding conductors.
- Power-On & Verification
- Restore power to the controller rack.
- Check the module’s discrete input data word — the “uncalibrated” alarm bit should be clear. If it’s set, the module requires calibration before use.
- Command each channel to a known test value and verify the output voltage with a multimeter.
- Confirm that the out-of-range and power loss alarm bits respond correctly when triggered.
- Clear any residual alarms via the discrete output command as documented in the module’s application guide.
Compatible Replacement Models
| Model | Compatibility Tier | Notes |
|---|---|---|
| 567LH-DP24 | ✅ Drop-in Replacement | Same part number — direct swap, verify calibration status |
| Other 567 series analog output modules | ⚠️ Verify with OEM | Different channel counts or output types (current vs. voltage) may require logic changes and rewiring |
| Third-party 8-channel isolated analog output modules | ❌ Hardware Mod Required | Different pinout, communication protocol, and alarm architecture — not recommended unless performing a full system migration |
Frequently Asked Questions (FAQ)
Q: What does the “out-of-range” alarm actually mean?
It means the host controller sent an engineering unit value that, when converted, would require the module to output a voltage approximately 50mV beyond its physical maximum or minimum. It’s not necessarily a hardware fault — it could be a scaling error in your control logic. Check your engineering unit-to-output mapping first.Q: Can I use this module without connecting all 8 channels?
Yes. Unused channels can be left unconnected. Just make sure your application logic doesn’t try to command outputs on channels that aren’t wired, as that could trigger unnecessary out-of-range alarms.Q: How do I clear an alarm once it’s been triggered?
The alarm bits are set in the module’s discrete input data. You clear them by sending the appropriate alarm-clear command through the module’s discrete output data word. The exact command format depends on your host controller’s communication protocol — check the REOTRON application documentation for your specific system.Q: Is this module still being manufactured?
Based on available information, this appears to be surplus stock. Confirm current availability and lead time directly with your supplier before placing an order. If you need a long-term supply strategy, discuss with your supplier whether a newer REOTRON series offers backward compatibility.Q: What happens if user power is lost to this module?
The module sets a “user power loss” alarm bit in its discrete input data. Your application logic should monitor this bit and take appropriate action — typically, this means flagging the associated outputs as unreliable and switching to a safe state for any field devices driven by those channels.Q: Do I need to recalibrate after replacing this module?
If the replacement module ships as “uncalibrated,” the alarm bit will tell you. Whether you need to perform a full recalibration depends on your process tolerance requirements. For critical analog outputs (e.g., valve positioning, servo references), I’d recommend verifying calibration against a known reference before putting the system back into production.
