YOKOGAWA YS1000 Series User Manual

59
IM 01B08B02-01EN
Troubleshooting
Troubleshooting
Table 10.2 List of Causes of Alarm Occurrence (Continued)
Type
Alarm
Display
Description Cause of Alarm Occurrence and Diagnosis Actions and Others
Process
alarm
PH1, PH2
High limit alarm for
PV
Process abnormality
PV1 or PV2 is at or above the high limit alarm
setpoint.
Recover the process to normal
conditions.
PL1, PL2
Low limit alarm for
PV
Process abnormality
PV1 or PV2 is at or below the low limit alarm
setpoint.
HH1, HH2
High-high limit alarm
for PV
Process abnormality
PV1 or PV2 is at or above the high-high limit
alarm setpoint.
LL1, LL2
Low-low limit alarm
for PV
Process abnormality
PV1 or PV2 is at or below the low-low limit
alarm setpoint.
DL1, DL2 Deviation alarm
Abnormal process deviation
|PV1 – SV1| or |PV2 – SV2| is at or above the
deviation alarm setpoint.
VL1, VL2 PV velocity alarm
Abrupt change in process
PV1 or PV2 velocity is at or above the velocity
alarm change setpoint or velocity alarm setting
time setpoint.
Table 10.3 List of Causes of Alarm Occurrence (Continued)
Type
Alarm
Display
Description Cause of Alarm Occurrence and Diagnosis
Actions and
Others
How to Clear
STC
alarm
SYS-ALM
System
abnormality
Prohibited combination control element was
executed.
Control function is not properly activated.
Current output is open.
STC stop (auto
startup is impossible
or stopped)
Continue STC
(auto startup is
impossible or
stopped)
PVOVR PV alarm PVvalueisbelow−6.3%orabove106.3%.
STC continues (auto
startup is impossible
or stopped)
MVLMT MV alarm
MV value is at the output limiter.
MV application signal span is inappropriate
before starting auto startup.
MV value was changed or limited after starting
auto startup.
OPERR
Operation
abnormality
Operation error during auto startup
IDERR
Identification
impossible
PV change was too small at auto startup.
PBLMT PB alarm
The proportional band has exceeded the
high/low limit.
STC continues (No
alarm is generated
during execution of
auto startup)
Eliminate the
cause of alarm.
STC = OFF
Run auto startup.
TILMT TI alarm Integral time has exceeded the high/low limit.
TDLMT TD alarm Derivative time has exceeded the high/low limit.
RTALM RT alarm Signal distribution ratio (RT) > 2 or RT < 0.5

YOKOGAWA YS1000 Series Specifications

General

Brand	YOKOGAWA
Model	YS1000 Series
Category	Controller
Language	English