Micro Motion Fisher Rosemount RFT9739, Инструкция по эксплуатации

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RFT9739 Rack-Mount Transmitter Instruction Manual
Theory of Operation
continued
Pressure compensation A pressure transmitter can be connected to the RFT9739 for pressure
compensation. The RFT9739 or an external source can supply power to
the pressure transmitter.
If the input is configured to indicate gauge pressure, the transmitter uses
the pressure input to account for effects of pressure on the flow tubes of
certain sensors. Not all sensors are affected by pressure. In this mode,
the pressure effect is calculated as the percent change in the flow rate
per psi change in pressure and/or the amount of change in density, in
g/cc, per psi change in pressure.
Output variables Measured variables can be output in a variety of ways from the
RFT9739. Mass or volume flow rate can be output as an isolated 4-20 or
0-20 mA signal over either of two sets of output terminals. Alternatively,
either mA output can be configured to indicate temperature, density,
pressure, event 1 or event 2.
Mass or volume flow pulses from the isolated frequency output terminals
can be scaled to 10,000 Hz for compatibility with PLCs, batch
controllers, and totalizers.
All measured variables, including totalizers for batch and inventory, can
be accessed digitally. The transmitter can use the Bell 202 physical layer
at 1200 baud superimposed on the primary mA signal and/or the
RS-485 physical layer at 1200 baud to 38.4 kilobaud. The transmitter
can use HART protocol over the Bell 202 or RS-485 physical layer,
Modbus protocol over the RS-485 physical layer, or HART over the Bell
202 layer and Modbus over the RS-485 layer.
A logic output can be programmed to indicate the flow direction, a fault
alarm, or a zero in progress condition. The transmitter operational status
is also indicated on the transmitter display.