The DIN-120 MODBUS current input modules are part of the DGH’s DIN-100 data acquisition module family. This input module converts analog voltage input signal from the 4-20mA range using the MODBUS RTU protocol to digital data at the rate of 8 conversions per second, storing the latest result in the buffer. The signal is transmitted to the computer or other processor-based controlling equipment using RS-485 port; if this is not available a DIN-191 converter to RS-232 can be used. The DIN-120 module can be directly connected to a sensor and perform signal conditioning, linearisation, scaling and conversion to both ASCII and MODBUS values. For extra security, it utilises a non-volatile EEPROM (Electrically Erasable Programmable Read Only Memory) to store all user-selectable settings, meaning the values are maintained in the event of power loss. The DIN-120 comes pre-set with default values of 300 baud, one start bit, eight data bits, one stop bit, no parity and any address recognized, but these values can be easily changed by the user. The modules require no special software and can be connected and started up quickly and easily, however a utility software is available at no extra charge if required. The DIN-120 can be mounted on a DIN-rail directly, without need for a mounting kit.

• Single channel analog-to-digital current input module
• RS-485 output
• Current input: 4-20mA
• Communicates using MODBUS RTU protocol
• User-selectable features include analog input range, baud rate, parity type and others
• Accuracy: ±0.04% of full scale
• Resolution: 0.04% of full scale
• Span temperature coefficient: ±50ppm/°C maximum
• Voltage drop: ±0.1V maximum
• 2 programmable single-pole digital filters for smoothing analog data
• Power requirements: Serial = 0.75W
• Temperature range -25°C to +70°C

The applications for the DIN-120 data acquisition modules include:

• Process monitoring and control
• Remote data logging to any host computer
• Product testing
• Interface to PLC