Siemens SITRANS FUG1010 IP65 NEMA 4X - Page 17

Manual Addendum
1010FMA-57
Digital P-Gen Applications Procedure Update
INTRODUCTION
The following Digital P-Gen applications procedure is to be added to the Data Span/Set/Cal Menu
section of the SITRANS liquid and gas flowmeter manuals listed below:
Gas Flowmeter Manuals
FUG1010 IP 65 (NEMA 4X) Clamp-On Gas Flowmeter manual (CQO:1010GCNFM-3)
FUG1010 IP 65 (NEMA 7) Compact Clamp-On Gas Flowmeter manual
(CQO:1010GCXFM-3)
FUG1010 IP 65 (NEMA 7) Compact Insert Gas Flowmeter manual (CQO:1010GXFM-3)
Liquid Flowmeter Manuals
FUH1010 IP 65 (NEMA 4X) Clamp-On Flowmeter manual (CQO:1010DVNFM-3)
FUH1010 IP 65 (NEMA 4X) Clamp-On Flowmeter manual (CQO:1010PVNFM-3)
FUH1010 IP 65 (NEMA 7) Compact Clamp-On Flowmeter manual (CQO:1010DVXFM-3)
FUH1010 IP 65 (NEMA 7) Compact Clamp-On Flowmeter manual (CQO:1010PVXFM-3)
A-1
DIGITAL P-GEN APPLICATIONS PROCEDURE
Adjusting the PGEN Output
The default setting for the Digital PGEN output provides a 5000 Hz frequency at an assumed maximum
velocity of 100 ft/sec. In certain cases it may be necessary to change this default PGEN value. For
example:
z If the PGEN signal cable is very long, then the added cable capacitance may prevent reliable RTU
pulse detection at or near 5000 Hz. In this case it may be necessary to decrease the PGEN (Pulses
/ Unit Volume) setting using the equation below.
MaxFlow
MaxFreq
UnitVolumePulses /
Where: MaxFreq = Maximum desired frequency (Hz)
MaxFlow = Maximum flow rate (Unit Volume / second)
z For very low operating flow rates, the pulse frequency may approach the 20 Hz limit of the PGEN
output. In this case it may be necessary to increase the PGEN (Pulses / Unit Volume) setting.
MinFlow
MinFreq
UnitVolumePulses /
Where: MinFreq = Minimum desired frequency (Hz). Must be greater than 20 Hz!
MinFlow = Minimum operating flow rate (Unit Volume / second)
Note: If STD VOL is selected then the “unit volume” for PGEN will represent Standard Volume,
not actual volume.
Forcing the PGEN Output Frequency
To test the operation of the flowmeter with an RTU, or other pulse counting device, it may be necessary
to force the PGEN output frequency, especially when the pipeline is not flowing during flowmeter
commissioning. This can be accomplished by setting the AnCal diagnostic value to a flow rate
corresponding to the desired frequency output. (Refer to the appropriate paragraph in your manual for
operation of the AnCal function.)