DGH D1450 Sensor to Computer Interface Thermistor Input Module

The D1450 thermistor input module is part of the DGH’s D1000 sensor to computer interface data acquisition module family. This input module converts the thermistor temperature sensor input signal from the 2252 Ohm or TD-series thermistor, to digital data, linearises and scales it in °C or °F, and communicates the values using the ASCII protocol to give digital output. The D1450 thermistor input module also contains a digital input/60Hz event counter (not applicable to D1540M) and two open-collector digital outputs which may be controlled by the host computer and used to control, for example, solid-state relays. 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 D1450 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 are designed to be compatible with all popular computers utilising RS-232C or RS-485 ports and no software is necessary to start using them, although the utility software is provided. The D1450 can be mounted on a DIN-rail if required (MK-1 mounting kit required) and can be combined with other D1000/D2000 modules to provide complete customised data acquisition system for given application.

• Analog-to-digital thermistor input module
• Choice of RS-232 or RS-485 output
• Choice of thermistors: 2252 Ohm at 25°C or TD Series
• Communicates using ASCII protocol
• User-selectable features include °C or °F, baud rate, parity type and others
• Accuracy: ±0.1°C for 2252Ω and ±0.2°C for TD series
• Resolution: 0.01° (C or F) for 2252Ω and 0.1°(C or F) for TD series
• Common mode rejection: 100dB at 50/60Hz
• Input protection to 30Vdc
• 1 Digital input/ Event counter, 2 Digital outputs
• Power requirements: Serial = 0.75W
• Temperature range -25°C to +70°C

The applications for the D1450 data acquisition modules include:

• Process monitoring and control
• Remote data logging to any host computer
• Product testing
• Direct connection to modems