Müller DRMA-S2/S4: universal DIN-rail transmitters for the cabinet

Müller Industrie-Elektronik DRMA-S2 and DRMA-S4: one DIN-rail transmitter for bridges, RTDs and standard signals

Control cabinets that collect signals from load cells, resistance thermometers and existing analogue loops often need a separate conditioner for each sensor type. Müller Industrie-Elektronik’s DRMA-S2 and DRMA-S4 DIN-rail transmitters aim to cover all of them with a single unit.

Four input families on one platform

The two devices form Müller’s Series 2 and Series 4 of universal DIN-rail transmitters. Both are built on MATU, the company’s existing transmitter electronics platform, and are intended primarily for mounting in control cabinets alongside the rest of the signal-processing hardware.

On the input side the transmitters accept strain gauge full bridges from 350 Ω, which makes them suitable for force and weighing sensors. They also take Pt100 and Pt1000 resistance thermometers in 2-, 3- or 4-wire connection, potentiometers from 350 Ω, and voltage signals of 0 to 1.9 V. A 0 to 10 V voltage input and a 0 to 20 mA current input are available as options. For plants that mix mechanical and thermal measurements, that range means fewer device types to stock and to learn.

The measured value is passed on as a 4-20 mA signal in 2-wire or 3-wire connection, or as 0 to 10 V in 3-wire connection. Limit values can also be configured as switching points, so a transmitter can trigger an action when a process value crosses a set threshold rather than only reporting it.

Display variant and OEM configuration

The difference between the two versions lies in the operator interface. The DRMA-S4 has a display and push buttons on the housing, which lets technicians configure and check the device directly in the cabinet. The DRMA-S2 has no local display.

Configuration is handled by Müller’s TrComm-Panel software. For OEM customers who build the transmitters into their own systems, the company offers this software as a white-label version, so it can be supplied under the machine builder’s name.

Electrical connection is made through pluggable 4-pin terminal strips, which allows a unit to be swapped without rewiring the cabinet. The housing is rated IP20, as is usual for equipment installed inside an enclosure. The supply voltage is given as 9 to 35 V DC; the product page also quotes 12 to 35 V DC elsewhere, so engineers should check the datasheet for the exact range of the chosen variant.

Key facts

• Inputs: strain gauge full bridge (from 350 Ω), Pt100/Pt1000 (2- to 4-wire), potentiometer (from 350 Ω), 0-1.9 V; optional 0-10 V and 0-20 mA
• Outputs: 4-20 mA (2- or 3-wire) or 0-10 V (3-wire), configurable switching points
• DRMA-S4 with display and buttons; DRMA-S2 without
• Pluggable 4-pin terminals, IP20, DIN-rail mounting
• Configuration via TrComm-Panel, available as white-label software for OEMs