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The image below shows Sensoray's Model 2612 -- a low-cost, modular measurement-and-control system designed for applications including machine control, industrial process control, building automation and remote data acquisition. It uses inexpensive Ethernet to connect a LAN to almost any number of I/O measurement and control points. All modules are DIN rail mountable.

The 2612 features four channels of strain gauge and/or RTD measurements . It reads the millivolt outputs of four strain/pressure gauges with 24-bit accuracy. Two voltage sense lines for the bridge input provide a true 6-wire measurement for the highest accuracy. The unit's microcontroller provides I/O services to the remote communication module client using category-5 cable. The cable supplies isolated serial communication and power to the 2612’s microcontroller.



Features set:
Analog Inputs
All measurements are made differentially to reduce common mode noise. All field wiring is connected directly to the 2608 via removable terminal blocks as shown in the photo. This minimizes downtime should it become necessary to replace a 2608 module. It also eliminates the need for separate terminal block assemblies.

RTD Temperature Inputs: RTD temperature sensors with alphas of 385 or 392 may be connected in a bridge circuit in place of a strain gauge. External resistors may be added to the this unit's terminal block to complete the bridge.

Auto standardize: The 2612 unit has automatic standardization circuitry that, from time to time, measures on-boards reference standards to update the gain and offset of each channel. Subsequent readings use the newest computed gain, offset and bridge input voltage. Factory calibration constants are stored in non-volatile memory so that it can be replaced without requiring field calibration.

Filtering: Digital filtering for 80dB rejection or more from 49Hz to 61Hz.

I/O Modules: A wide selection of I/O module types are available from this and other vendors. Each I/O module type may have a specialized function such as analog I/O, thermocouples, relays, digital I/O, etc. A low-cost category-5 patch cable connects each I/O module to its Communication Module. Any combination of I/O modules may be connected to a Communication Module.

All I/O modules should provide on-board DC/DC converters to power module circuitry. This helps prevent ground loops and associated common-mode voltage problems when the I/O modules are distributed over long distances. Also, the inter-module communication circuits are optically isolated so as to eliminate communication ground loops.

More info here.