The MTT MS3705 is a slim plug-in alarm setter that watches a DC current or voltage signal and switches two independent, isolated relay outputs when the signal crosses a set point. Each set point is dialed in on a front-accessible rotary switch as a percentage of the input span, so alarm thresholds can be adjusted on site without special tools or a laptop, and built-in hysteresis stops the relay from chattering when the signal sits right at the trip point.
Because the two relay outputs are electrically isolated from the input, from the power supply, and from each other, the MS3705 can drive two independent alarm circuits, such as a low and a high limit, or a local indicator and a remote annunciator, from a single measured signal. Like the rest of the plug-in transmitter range, it clips into its own socket base so the unit can be swapped for calibration or replacement in seconds without disturbing the field wiring, and flexible AC or DC power plus wall or DIN rail mounting make it easy to fit into an existing panel.
