Module plugs into a ROC300-Series Remote
Operations Controller or a FloBoss%uF8EA 407 Flow
Manager and is used for monitoring the temperature signal from an RTD sensor within a fixed range.
The module can accommodate the signal from a 2-wire, 3-wire, or 4-wire RTD; however, the design of the module does not permit a 4-wire RTD to provide any more accuracy than a 3-wire RTD.
An RTD is a precision, temperature-dependent resistor, whose resistance increases with temperature.
The RTD input module works by supplying a small current to the RTD and measuring the voltage drop across it.
The voltage is converted to temperature in the ROC or FloBoss firmware according to the temperature curve of the RTD.
To avoid a loss in accuracy and possible damage to the RTD input module from induced voltages, sensor wires should be of equal length and kept as short as possible (typically 100 feet or less).
Because the RTD module uses low voltages, the possibility of lightning damage is increased. Although a Lightning Protection Module (see specification sheet 5:LPM) does not protect the RTD module, it does help protect the I/O module rack and other I/O modules installed in the rack.
Field wiring connections are made through a separate terminal block that plugs in next to the module. This design facilitates replacement of the module without disconnecting field wiring.