KROHNE ALTOSONIC V EN - Manual (Page 19)

ALTOSONIC V
Operating Manual rev02 E 7.30850.34.00 Page 19 of 106
Deviation limit is set default to –0.5…+0.5 % of mean V.O.S.
Possible causes are:
•
Local density variations due to sludge, mixtures or temperature variations
• Empty pipe
•
Problem with converter
•
Problem with sensor
Common checks are:
• Flow and sound velocity per channel
4. COMMU, Communication failure between UFP and UFC (rs485).
The communication is checked on communication errors. The incoming RS485 data is checked on
validity. Single errors are skipped (COMFA’s) but if there are more than 120 consecutive requests
failing this alarm is raised.
Possible causes are:
•
if all channels fail there is probably no power supply to the UFC
•
if all channels fail it is probably caused by a malfunction of the connection between UFP and
UFC
• if some channels fail the problem is in the specific converter of the UFC
• The specific converter is in it’s configuration menu
•
The specific converter is not configured properly
Common checks are:
•
Power supply UFC
• Converter displays
•
If a new converter is installed, check the configuration
•
Cable
•
Connections
• Check the converter by exchanging the connections of a good converter for a probably bad
converter. Note that the channel number is configured in the converter
5. COMMFA, single communication failures until COMMU is reached
Channel error types 1 to 4 are used to make the General Flow alarms. On General Flow alarm the
REAL profile is used to correct the failing channels.
If COMFA’s occur then the previous measurement on that channel is used for calculation.
Possible causes are:
- Multiple rapid window changes on slower CPU’s
- EMC distortion through poorly connected wiring.
INPUT ALARMS shows:
Each parameter as stated below INPUT ALARMS has alarm settings in the CLNT0300.dat file.
If the alarm is enabled and the parameter is used in the calculation then on alarm the time of
occurrence is counted.
When the parameter is in manual override, the time of occurred manual override is counted.
CALCULATION shows:
When using the calculation for the standard volume by API standards the alarm is on if the density is
out of range for the API group that is used (see chapter 5).
GENERAL FLOW shows:
The combined channel errors give an alarm on “1-4 channels” down and “all channels down” in time of
occurrence.
If the UFP has a power failure then the time between start up and program running is calculated and
added at start up of the UFP-Program.