We had an enquiry from a customer building out a skid-mounted panel that only had 24V DC available — no AC mains was being run to that panel at all. They needed to isolate and re-range a 4-20mA signal the same way our standard signal conditioner does, but without pulling in a separate AC supply just for one instrument.
Most of our slim plug-in signal conditioners are happy running on AC or DC, which covers most panels. But on a DC-only control system — common on skids, remote enclosures, or battery/solar-powered sites — specifying a unit that still lists an AC option is unnecessary, and running a small AC step-down just to power one transmitter adds cost and another point of failure for no real benefit.
For this, we would normally recommend the MTT MS3704-D1, a slim plug-in high-level signal conditioner built to run on 11-27V DC only. It accepts the same range of DC current inputs (4-20mA, 2-10mA, 1-5mA, 0-20mA, 10-50mA) and DC voltage inputs (0-1V up to 0-10V) as the standard MS3704, and converts them into a clean, isolated single or dual output with the same accuracy and response time. Because it’s built specifically for a DC supply, it drops straight into an existing 24V DC panel bus without needing any separate AC wiring, and 4-way isolation between input, outputs, power, and ground keeps the signal clean.
Before we quote, we would normally check:
- Confirm only DC power (11-27V DC) is available at the panel
- Exact input signal type and range (current or voltage)
- Whether you need a single output or isolated dual output
- Output signal range required
Hope this helps — send us your input signal and the output you need, and we can confirm the right model.
| Power Supply | 11-27V DC, approx. 0.8W max (single output) or 1.2W max (dual output); 160mA fuse |
| Input Types | 4-20mA DC, 2-10mA DC, 1-5mA DC, 0-20mA DC, 10-50mA DC, or 0-1V/0-5V/1-5V/0-10V DC (configurable) |
| Input Resistance | 100Ω to 1MΩ minimum, depending on signal type |
| Allowable Input | 30V DC max. continuous (voltage inputs); 40mA DC max. continuous (current inputs) |
| Output | Configurable single or isolated dual output, same range options as input |
| Output Load | Up to 750Ω for single 4-20mA output; 550Ω/350Ω for dual outputs |
| Zero & Span Adjustment | Approximately ±5% of span |
| Isolation | 4-way isolation between input, Output 1, Output 2, power, and ground |
| Accuracy | Better than ±0.1% of span (at 25°C±5°C) |
| Response Time | 85ms maximum (0-90%); 10ms with /K fast-response option |
| CMRR | Minimum 100dB (500V AC, 50/60Hz) |
| Insulation Resistance | 100MΩ minimum at 500V DC |
| Dielectric Strength | 2000V AC for one minute |
| Dimensions (W x H x D) | 29mm x 86mm x 125mm |
| Weight | Main unit 120g; socket 80g |
| Mounting | Wall or DIN rail mounting, plug-in socket base |
| Operating Temperature | -5 to 55°C ambient |
| Operating Humidity | 5-90% RH, non-condensing |
Frequently Asked Questions
What is the MTT MS3704-D1 used for?
It’s a signal conditioner and isolator for DC current or voltage signals, built to run on 11-27V DC power — useful in panels that have no AC mains available.
What’s the difference between the MS3704-D1 and the standard MS3704?
They condition the same input signals with the same accuracy, but the standard MS3704 accepts AC or DC power, while the MS3704-D1 is built for 11-27V DC power only. Use the D1 when your panel only has DC available.
Can the MS3704-D1 be powered from a 24V DC control system bus?
Yes — it’s designed for exactly that, accepting 11-27V DC, which covers a standard 24V DC supply with normal tolerance.
Is a fast-response version of the MS3704-D1 available?
Yes — the standard response time is 85ms, and a /K fast-response option brings that down to 10ms.
How do I know which MS3704 model I need?
Tell us what power is available at your panel (AC, DC, or both), your input signal type and range, and the output signal your PLC or DCS expects. We’ll confirm the right model before you order.
Download MTT MS3704-D1 Slim Plug-In High-Level Signal Conditioner information here
Spec Sheet: MTT MS3704-D1 Spec Sheet
Manual: MTT MS3704-D1 Manual
