Description
Product Description – Triconex 3301 Digital Input Module
A TMR module for reliable digital inputs
The Model 3301 is a Triple Modular Redundant (TMR) digital input module. Specifically, it uses three isolated electronic channels. As a result, each channel processes field data independently.
How it shares data
Each channel puts processed data into an array. Then it sends this array to its MP when asked. After that, the MPs vote on the data. Finally, they pass the voted result to your application.
Smart diagnostics keep you safe
This module runs full diagnostics on every channel. If any channel fails, the Fault indicator turns on. Consequently, this also activates the system alarm. However, note carefully: the Fault light means only one channel has a problem, not the whole module.
Handles faults like a pro
The DI Module constantly checks its ability to detect signal changes. Therefore, it works correctly with one single fault. Moreover, it may even keep working with multiple faults. Additionally, it supports a hot-spare module.
Easy and safe installation
Each module is mechanically keyed. Thus, this prevents wrong installation in a configured baseplate. For instance, use it with Model 2301 baseplate (for typical jobs). Alternatively, use the DI External Termination Baseplate (for high voltage or hazardous locations).
Technical Specifications (At a Glance)
Parameter Value
Brand Triconex
Model 3301
Type TMR Digital Input Module
Points 32, commoned
Nominal Voltage 24 VDC
Operational Range 15–30 VDC
Max Voltage (no damage) 33 VDC
Max Reverse Voltage –0.6 VDC
Input Delay <10 ms (On to Off or Off to On)
Time Constant 6.4 ms, –3dB @ 25Hz
Input Impedance (no baseplate) >30 kΩ
Input Impedance (with baseplate) >3 kΩ
Input Power @24 VDC 0.2 W per point
Input Power @33 VDC 0.5 W per point
Off Region 0–5 VDC
Transition Region 6–14 VDC
On Region 15–30 VDC
Diagnostic Type Force-to-value (FVD)
Test Speed <2 ms per test
Max Toggle Rate for full coverage <20 per second
FVD Off State Glitch Duration <2 ms
FVD Off State Glitch Magnitude ≤36% of test voltage
Output Impedance 0–5 VDC, >100 kΩ
ADC Scan Time (all 32 points) <1 ms
FE to PE Isolation 500 VDC minimum
FE to Logic Ground Isolation 800 VDC minimum
Installation & Compatibility
First, mount the module in a configured Tricon baseplate. The keying prevents wrong insertion.
Next, choose your baseplate:
Model 2301 – for typical applications
DI External Termination Baseplate – for high-voltage work (with Solid State Relay Input ETP) or hazardous locations (with Model 9573-610 ETP)
Additionally, the module works with a hot-spare. Therefore, no need to power down for replacement.
It also pairs with Modicon Quantum systems when using the correct backplane.
Diagnostic Abilities
Force-to-value (FVD) tests run in under 2 ms.
Meanwhile, the module checks its own ability to see signal changes.
A Fault indicator lights up per channel, not for the whole card.
As a result, the system alarm activates on any detected channel failure.
Finally, it works fine with one fault. In fact, it may keep going with multiple faults.
Typical Applications
Safety systems needing TMR fault tolerance
24 VDC digital signal monitoring
High-voltage field input isolation (with proper baseplate)
Hazardous location input (with Model 9573-610)
Backup digital input with hot-spare support
Frequently Asked Questions (FAQ)
Q1: What happens if one channel fails but the other two are fine?
A1: The module keeps working correctly. Consequently, the Fault indicator will light for that one channel. Therefore, you can plan a replacement without stopping the system.
Q2: I see a Fault light, but all my inputs read correctly. Is this normal?
A2: Yes, this is normal. Specifically, the Fault light means one channel has an issue, not the whole module. Meanwhile, the other two channels still give correct data. However, you should order a replacement soon to restore full TMR protection.
Q3: Can I use this module with a 12V DC sensor?
A3: No, you cannot. 12V DC falls into the transition region (6–14 VDC). Thus, the module may not read it reliably. Instead, use a sensor that gives 15–30 VDC for a solid On signal, or 0–5 VDC for Off.
Q4: What is the warranty and shipping method?
A4: We provide 12 months warranty from delivery. It covers manufacturing defects only. For shipping, we use FedEx, UPS, or DHL. You will get a tracking number. Additionally, keep the module in its original packaging for any warranty claim.
Q5: How many spare modules should I keep for a system with 10 DI modules?
A5: Keep at least one hot-spare 3301 module. If your system runs 24/7 in a harsh environment, keep two spares. Why? Because this avoids long downtime while waiting for shipment. Also, test your spare once every 6 months by swapping it in.
Selection Guide (Buying Advice)
Choose the 3301 if: You need TMR fault tolerance. Your inputs are 24 VDC nominal (15–30 VDC range). You want per-channel diagnostics. You may have high voltage or hazardous area sensors with the right baseplate.
Do not choose the 3301 for: AC inputs. Very fast toggling above 20 Hz. Voltages below 15 VDC or above 33 VDC. Non-TMR systems that do not need triple redundancy.
Spare module advice: Buy one spare for every 10 working modules. Then label the spare with its purchase date. Finally, rotate it into service once per year to confirm it works.
Baseplate tip: Order the correct baseplate at the same time. Otherwise, the wrong baseplate will not fit due to mechanical keying.
For inquiries, contact us:
+86 158 8020 0923 (WhatsApp)
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