DGH D1300M Modbus with Thermocouple Input Module Series

The D1300M thermocouple input module is part of the DGH’s D1000M Modbus sensor to computer interface data acquisition module family. This input module converts the thermocouple temperature sensor input signal from the choice of 8 different thermocouple types (J, K, T, E, R, S, B and C) to digital data, linearises and scales it in °C or °F, and communicates the values using the Modbus RTU protocol to give digital output. The D1300M thermocouple input module also contains two digital inputs which may be read by the host computer to sense the state of a remote digital signal, such as state of limit or safety switches and three open-collector digital outputs (or HI/LO alarms) 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 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. Upon startup, a simple command can be used to setup desired baud rate, parity and other parameters. The D1300M can be mounted on a DIN-rail if required (MK-1 mounting kit required) and can be combined with other D1000M/D2000M modules to provide complete customised data acquisition system for given application.

• Analog-to-digital thermocouple input module
• Choice of RS-232 or RS-485 output
• Choice of 8 different thermocouple types: J, K, T, E, R, S, B, C (factory set)
• Communicates using Modbus RTU protocol
• User-selectable features include °C or °F, baud rate, parity type, channel address and others
• Accuracy (overall, error from all sources, between 0-40°C ambient): ±1.0°C maximum (J, K, T, E) and ±2.5 °C maximum (R, S, B, C)(300°C TO FS)
• Resolution: ±1°
• Common mode rejection: 100dB at 50/60Hz
• Input impedance: 100MΩ minimum
• Lead resistance effect: <20μV per 350Ω
• Open thermocouple and overrange indication
• Autozero and auto-calibration
• Up to 246 multidrop modules per host serial port (RS-485 only)
• Input burnout protection to 250Vac
• Automatic cold junction compensation and linearisation
• 2 Digital inputs with ±30V Voltage levels, switching levels of 3.5V minimum, low, 1.0V maximum and internal pull up resistors for direct switch input
• 3 Digital outputs, open collector to 30V, 30mA maximum load
• Power requirements: Serial = 0.75W
• Temperature range -25°C to +70°C

The applications for the D1300M data acquisition modules include:

• SCADA
• Data monitoring
• Data loggers
• PLC’s
• Process controllers and instrumentation