The MTT MS3704IS is a slim plug-in signal isolator with selectable 4-20mA DC current or 1-5V DC voltage input and output, set at the factory via the ordering code to match whichever signal combination a given application needs — current-to-voltage, voltage-to-current, or straight isolation with no signal type change.
4-way isolation between input, output, power, and ground breaks the direct electrical connection between the source instrument and the receiving equipment, preventing ground loops and interference regardless of which signal types are selected. Input resistance is 1MΩ minimum on the voltage input or 250Ω on the current input, and output load capability is up to 750Ω for a current output or 2mA maximum for a voltage output. Accuracy is better than ±0.1% of span at 25°C±5°C.
Power options cover 100-240V AC, 24V DC, or 100-240V DC, so the unit fits most existing panel supplies without extra conversion hardware. Like the rest of the plug-in transmitter range, the MS3704IS mounts on its own DIN-rail plug-in socket base, letting the unit be swapped for calibration or replacement in seconds without disturbing the field wiring. Its compact footprint suits installations where several conditioners need to sit side by side on the same rail.
| Input Types | 4-20mA DC or 1-5V DC (selectable via ordering code) |
| Input Resistance | 1MΩ minimum (voltage input); 250Ω (current input) |
| Allowable Input | 30V DC max. continuous (voltage); 40mA DC max. continuous (current) |
| Output | 4-20mA DC or 1-5V DC (selectable via ordering code) |
| Output Load | 2mA maximum (voltage output); 750Ω maximum (current output) |
| Isolation | 4-way isolation between input, output, power, and ground |
| Power Supply | 100-240V AC (85-264V AC, 47-63Hz, 4.0VA max), 24V DC ±10% (1.2W max), or 100-240V DC (4.8W max) |
| Accuracy | Better than ±0.1% of span (at 25°C±5°C) |
| Temperature Effect | Better than ±0.2% of span per 10°C change |
| Response Time | 85ms maximum (0-90%) |
| CMRR | Minimum 100dB (500V AC, 50/60Hz) |
| Insulation Resistance | 100MΩ minimum at 500V DC |
| Dielectric Strength | 2000V AC for one minute |
| Housing | ABS resin (UL 94V-0) |
| Dimensions (W x H x D) | 29mm x 86mm x 125mm |
| Weight | Main unit up to 120g; socket up to 80g |
| Mounting | Wall or DIN rail mounting, plug-in socket base |
| Terminals | M3.5 screw terminals, 0.8-1.0Nm torque |
| Operating Temperature | -5 to 55°C ambient (storage: -10 to 60°C) |
| Operating Humidity | 5-90% RH, non-condensing |
| Standards | CE marked; EMC Directive 2014/30/EU; Low Voltage Directive 2014/35/EU; Installation Category II |
Frequently Asked Questions
What is the MTT MS3704IS used for?
It converts between 4-20mA current and 1-5V voltage signals, with isolation between input and output — useful when a transmitter’s output type doesn’t match what the receiving PLC or DCS input card accepts.
Can the MS3704IS convert 4-20mA to 1-5V and also 1-5V to 4-20mA?
Yes — both input and output are selectable via the ordering code, so it can be configured for either direction, or to just isolate a signal without changing its type.
What’s the difference between the MS3704IS and the standard MS3704?
The standard MS3704 covers a much wider range of input and output signal types. The MS3704IS is a simpler, more compact unit focused specifically on 4-20mA and 1-5V conversion.
Does the MS3704IS isolate the signal even if the input and output types are the same?
Yes — isolation is built in regardless of whether you’re converting between signal types or keeping the same type on both sides.
How do I know which MS3704IS configuration I need?
Tell us your source signal type and the type your receiving equipment needs, and we’ll confirm the right ordering code before you order.
Download MTT MS3704IS Slim Plug-In High-Level Signal Conditioner information here
Spec Sheet: MTT MS3704IS Spec Sheet
Manual: MTT MS3704IS Manual
