This pH transmitter/regulator in a panel-mounted housing is a compact yet modular device that can tackle a wide range of tasks due to its flexibility (including 3 slots for optional boards). The main input is designed for sensors measuring pH values or redox voltage. In addition to conventional glass sensors, ISFET sensors or sensors for ammonia concentration can be used. The second analog input (compensation input) can accommodate resistance thermometers Pt100 or Pt1000, NTC/PTC, or standard signals of 0(4) to 20 mA, or 0 to 10 V. The two binary inputs can serve as initiators for actions (such as HOLD, keyboard lock) or, when connected to pulse generators (like paddle wheel sensors), for flow measurement. The high-contrast graphic display allows for the representation of input signals in digits or as a bar graph. The clear text display of parameters makes operation easy to understand and secure. The device can be configured as a two-point, three-point, three-point step controller, or as a continuous controller, offering versatile applications. The controller's software also includes a parameter set switching feature and a math module. For convenient configuration via a PC, a setup program is available. In addition to the standard inputs and outputs already described, the device also features an analog output. Power supply is provided through a switching power supply AC 110 to 240 V +10/-15 % 48 to 63 Hz. Electrical connections are made at the rear via screw terminals.