Emerson 1500 Pacemaker User Manual


 
Overview
AO Cutoff (Analog Output Cutoff) specifies the lowest mass flow rate, volume flow rate, or
gas standard volume flow rate that will be reported through the mA output. Any flow rates
below AO Cutoff will be reported as 0.
Restriction
AO Cutoff is applied only if mA Output Process Variable is set to Mass Flow Rate, Volume Flow Rate, or Gas
Standard Volume Flow Rate. If mA Output Process Variable is set to a different process variable, AO Cutoff is
not configurable, and the transmitter does not implement the AO cutoff function.
Procedure
Set AO Cutoff as desired.
The default value for AO Cutoff is 0.0 g/sec.
Tip
For most applications, the default value of AO Cutoff should be used. Contact Micro Motion customer
service before changing AO Cutoff.
Interaction between AO Cutoff and process variable cutoffs
When mA Output Process Variable is set to a flow variable (for example, mass flow rate or
volume flow rate), AO Cutoff interacts with Mass Flow Cutoff or Volume Flow Cutoff. The
transmitter puts the cutoff into effect at the highest flow rate at which a cutoff is
applicable.
Example: Cutoff interaction
Configuration:
mA Output Process Variable = Mass Flow Rate
Frequency Output Process Variable = Mass Flow Rate
AO Cutoff = 10 g/sec
Mass Flow Cutoff = 15 g/sec
Result: If the mass flow rate drops below 15 g/sec, all outputs representing mass flow will
report zero flow.
Example: Cutoff interaction
Configuration:
mA Output Process Variable = Mass Flow Rate
Frequency Output Process Variable = Mass Flow Rate
AO Cutoff = 15 g/sec
Mass Flow Cutoff = 10 g/sec
Integrate the meter with the control system
Configuration and Use Manual 75