Measurement Units

Emerson ROCPlus field devices can be configured to display values in defined sets of imperial/US or metric measurement units. Once you have defined a unit set, the field device tells CygNet what unit set it is running and CygNet displays the appropriate fields on remote device editor dialog boxes. For Emerson ROCPlus devices, this information is viewed on the Station Parameters data group Advanced page.

To Set Unit Type

For Emerson ROCPlus remote devices, set the unit type by doing the following:

1. In CygNet Explorer, open your Device Definition Service (DDS).
2. Click the remote device you want to configure.
3. In the remote device editor, click the Data Group page.
4. Double-click Station Parameters and click the Advanced page.
5. Click Edit, then select the US or Metric option under Units.
6. When you are done, click Send to RTU.

Measurement Units List

The following table categorizes units into Imperial/US and Metric unit sets.

Item Name	Imperial/US Unit Set	Metric Unit Set
Alarm Deadband	MCFD (thousand cubic feet per day)	Km3D (thousand cubic meters per day)
Atmospheric Pressure	psi (pound-force per square inch )	KPa (kilopascal)
Base Pressure	psi (pound-force per square inch )	KPa (kilopascal)
Base Temperature	F (degree Fahrenheit)	C (degree Celsius)
Differential Pressure	inH2O (inch of water)	KPa (kilopascal)
Elevation	ft (foot)	m (meter)
Energy Includes various types of energy, temperature, and volume.	MMBTU (million British thermal units)	GJ (gigajoule)
Flow	MCFD (thousand cubic feet per day)	Km3D (thousand cubic meters per day)
Flow Time	mins
Grav. Acc. Correction	ft/s2 (feet per second squared)	m/s2 (meter per second squared)
Heating Value Mass	BTU/Lb (British thermal unit per pound)	MJ/kg (megajoule per kilogram)
Heating Value Volume	BTU/CF (BTU per cubic foot)	MJ/m3 (megajoule per cubic meter)
High Alarm	MCFD (thousand cubic feet per day)	Km3D (thousand cubic meters per day)
High Differential Pressure Setpoint	inH2O (inch of water)	KPa (kilopascal)
K-Factor	Pulses/Cf	Pulses/M3
Latitude	Deg (degree)	Deg (degree)
Local Grav Accel	ft/s2 (feet per second squared)	m/s2 (meter per second squared)
Low Alarm	MCFD (thousand cubic feet per day)	Km3/D (thousand cubic meters per day)
Low Differential Pressure Setpoint	inH2O g (inch of water gauge)	KPa (kilopascal)
Low Flow Cutoff	inH2O (inch of water)	KPa (kilopascal)
Mass	lb (pound)	kg (kilogram)
Orifice Diameter	in (inch)	mm (millimeter)
Orifice Temperature	F (degree Fahrenheit)	C (degree Celsius)
Pipe Diameter	in (inch)	mm (millimeter)
Pipe Ref Temp	F (degree Fahrenheit)	C (degree Celsius)
Static (Line) Pressure	psi (pound-force per square inch )	KPa (kilopascal)
Temperature Includes various types of energy, temperature, and volume.	F (degree Fahrenheit)	C (degree Celsius)
Volume Includes various types of energy, temperature, and volume.	MCF (thousand cubic feet)	Km3 (thousand cubic meters)
Viscosity For Emerson ROCPlus remote devices, users can control the type of viscosity units used. Viscosity values in the range 0.005 to 0.5 are displayed as metric (i.e., cp) by default and no conversion occurs. If a viscosity value is outside of this range, the units are set to imperial or metric, depending on how the device is configured, and no conversion occurs. If you want to pass through units for this value range, set the "FMS Configuration" (FmsConfig) data group attribute PassVisc to "true". If you do not want to pass through units for this value range and instead want them to be set by CygNet (the default behavior), set the attribute value PassVisc to "false" or remove PassVisc.	Lbm/Ft-Sec (pound mass per foot second)	cp (centipoise)