Appendix F. CPEC300 Series Diagnostics
F-6
•
ERROR: Valve flow is not at setpoint - Check buff_depth
is displayed
if the valve flow is outside the acceptable range (
valve_flow_OK =
False
) and the processing has fallen too far behind (
buff_depth_OK
= False
). A processing delay does not always cause a valve flow error.
In some cases, the processing may catch up before the valve flow
drifts too far from the setpoint. For additional information see notes
on bit 4.
•
ERROR: Valve flow is not at setpoint
is displayed if the valve flow is
outside the acceptable range and the problem cannot be explained by
one of the conditions listed above. For additional troubleshooting
advice, see notes on bit 3.
F.2 Status Boolean Variables
CPEC300 system status information is also provided as discrete Boolean
variables that indicate whether or not a particular subsystem has a problem.
Most of these variables have names that end in “OK.” These variables are
intended to bridge the gap between the user-friendly “status text variables” and
the compact yet cryptic “diagnostic words.” They provide an intermediate
level of information for real-time troubleshooting and allow a CPEC300
system to store statistics on various conditions.
EC_mode
This Boolean variable is intended for screening time-series data for post-
processing.
EC_mode
=
True
if the sample pump is on and no zero/span
sequence is running (see Appendix
). Records
for which
EC_mode
=
False
, should be excluded from EC calculations. This
variable is also used by the CPEC300 program to determine the relevance of
some of the error conditions. For example, the pump flow is relevant only in
EC mode, but the battery voltage is always relevant. This relevance based on
EC_mode
determines whether or not a particular bit will be set in
diag_cpec
(see Appendix
(p. F-1)
, for details).
BattVoltOK
Boolean variable
BattVoltOK
is equivalent to bit 9 of
diag_cpec
. If
BattVoltOK
is false, this indicates the CPEC300 system supply voltage has
fallen below the shutdown limit and has not risen to an acceptable restart level.
See notes on bit 9.
irga_OK
Boolean variable
irga_OK
is equivalent to bit 8 of
diag_cpec
. If an IRGA
problem is detected,
irga_OK
=
False
and bit 8 of
diag_cpec
will be set. See
notes on bit 8 and on
irga_status
, which may give additional information
about the IRGA problem.
sonic_OK
Boolean variable
irga_OK
is equivalent to bit 8 of
diag_cpec
. If an IRGA
problem is detected,
irga_OK
=
False
and bit 8 of
diag_cpec
will be set. See
notes on bit 8 and on
irga_status
, which may give additional information
about the IRGA problem.
pump_flow_OK
Boolean variable
pump_flow_OK
=
True
if the pump flow (
pump_flow)
is
within 10% of the setpoint
PUMP_SETPT.
It is set to
False
if it is outside this
range.
