1190
11 PROCESS CONTROL INSTRUCTIONS
11.1 Overview
Details of Alarm detection (ALM) are shown below.
■Disable alarm detection (INH)
This disable alarm detection of each item. The alarms whose detection is disabled by INH are not detected.
INH bits b0 to b11 correspond to ALM bits b0 to b11.
■Control mode (MODE)
The process control instructions have the following control modes that satisfy the following operations in a system connected
to the operator station, programmable controller, host computer, and machine side operation panel. Set only 1 bit of flag for
the control mode (MODE).
Details of the control mode (MODE) are given below.
Item Name Status Set by
SPA Stop alarm Loop STOP state
• Loop mode MAN is entered.
• Loop stop processing is performed for the output value (BW) and alarm signal.
User
DMLA Output variation rate limit
alarm
As the result of checking input data using the variation rate limiter, the output variation rate limit
has been exceeded.
System
OOPA Output open alarm The operation output signal is in open state due to disconnection. System
SEA Sensor alarm Sensor error alarm System
HHA Upper upper limit alarm The process value exceeds the upper limit defined for the process equipment. System
LLA Lower lower limit alarm The process value underruns the lower limit defined for the process equipment. System
PHA Upper limit alarm As the result of upper limit checking, the process value exceeds the upper limit. System
PLA Lower limit alarm As the result of lower limit checking, the process value underruns the lower limit. System
DPPA Positive direction variation
rate alarm
The variation rate exceeds the variation rate range on an upward trend. System
DPNA Negative direction variation
rate alarm
The variation rate underruns the variation rate range on a downward trend. System
DVLA Large deviation alarm The result of a deviation check shows that the deviation limit is exceeded. (The deviation check
determines whether the deviation has been reduced completely underrunning the alarm value.
To do so, when the deviation has been reduced to a certain value range from the alarm value,
the large deviation alarm is released.)
System
MHA Output upper limit alarm As the result of checking with the upper/lower limiter, the value output by the limiter exceeds the
output upper limit.
System
MLA Output lower limit alarm As the result of checking with the upper/lower limiter, the value output by the limiter underruns
the output lower limit.
System
(1) Tracking flag (Do not rewrite the tracking flag.)
(2) Alarm detection disabled
Control mode Description Application
MAN (MANUAL) • Manual operation from operator station
• SV and MV can be set.
Used for monitoring and control from the
operator station.
AUT (AUTOMATIC) • Automatic operation
• SV can be set.
• MV cannot be set.
CAS (CASCADE) • Cascade operation
• SV nor MV cannot be set.
CMV (COMPUTER MV) Automatic MV setting from host computer Loop control from the host computer is possible.
Used to operate and monitor the control mode on
the operator station.
CSV (COMPUTER SV) Automatic SV setting from host computer
(1)
(2)
MLI
MHI
DVLI
DPNI
DPPI
PLI
PHI
LLI
HHI
SEI
OOPI
DMLI
ERRI
TRKF
b15 b13
......
b0b1b2b3b4b5b6b7b9b10b11 b8
b15 b0b1b2b3b4b5b6b7b8b9b10
LCM
LCA
LCC
MAN
AUT
CAS
CMB
CAB
CCB
CMV
CSV
...
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