Emerson MMI-20019043 Satellite Radio User Manual


 
Frequency output problems and recommended actionsTable 12-7:
Problem Possible causes Recommended actions
No frequency output Stopped totalizer
Process condition below cutoff
Fault condition if fault action is set to in-
ternal zero or downscale
Slug flow
Flow in reverse direction from config-
ured flow direction parameter
Bad frequency receiving device
Output level not compatible with receiv-
ing device
Bad output circuit
Incorrect internal/external power con-
figuration
Incorrect pulse width configuration
Output not powered
Wiring problem
Verify that the process conditions are below
the low-flow cutoff. Reconfigure the low-flow
cutoff if necessary.
Check the Fault Action settings. See
Section 12.19.
Verify that the totalizers are not stopped. A
stopped totalizer will cause the frequency
output to be locked.
Check for slug flow. See Section 12.25.
Check flow direction. See Section 12.23.
Verify that the receiving device, and the wir-
ing between the transmitter and the receiv-
ing device.
Verify that the channel is wired and config-
ured as a frequency output.
Verify the power configuration for the fre-
quency output (internal vs. external).
Check the pulse width. See Section 12.20.
Perform a loop test. See Section 12.12.
Consistently incorrect
frequency measure-
ment
Output not scaled correctly
Incorrect flow measurement unit config-
ured
Check the frequency output scaling. See
Section 12.21.
Verify that the measurement units are con-
figured correctly for your application.
Erratic frequency out-
put
Radio frequency interference (RFI) from
environment
Check for radio frequency interference. See
Section 12.13.
12.8 Use sensor simulation for troubleshooting
When sensor simulation is enabled, the transmitter reports user-specified values for mass
flow, temperature, and density. This allows you to reproduce various process conditions or
to test the system.
You can use sensor simulation to help distinguish between legitimate process noise and
externally caused variation. For example, consider a receiving device that reports an
unexpectedly erratic flow value. If sensor simulation is enabled and the observed flow rate
does not match the simulated value, the source of the problem is likely to be somewhere
between the transmitter and the receiving device.
Important
When sensor simulation is active, the simulated value is used in all transmitter outputs and
calculations, including totals and inventories, volume flow calculations, and concentration
calculations. Disable all automatic functions related to the transmitter outputs and place the loop in
manual operation. Do not enable simulation mode unless your application can tolerate these effects,
and be sure to disable simulation mode when you have finished testing.
Troubleshooting
226 Micro Motion
®
Model 2700 Transmitters with Analog Outputs