HIMA HIMax User Manual

5 Programming HIMax System
HI 801 001 E Rev. 4.01 Page 66 of 122
Column Description Range of Values
LL Alarm Priority Priority of the lowest limit; default value: 500 0...1000
LL Alarm Ac-
knowledgment
Required
Activated
The user must confirm that the lowest limit value
has been exceeded (acknowledgment).
Deacti-
vated
The user may not confirm that the lowest limit
value has been exceeded.
Default value: Deactivated
Checkbox activated,
deactivated
Alarm Hysteresis
The hysteresis avoids that many events are continuously cre-
ated when the process value often oscillate around a limit.
depending on the
global variable type
Table 22: Parameters for Scalar Events
NOTICE
Faulty event recording due wrong parameter settings possible!
Setting the parameters L Alarm Value and H Alarm Value to the same value can
cause an unexpected behavior of the event recording since no normal range exists
in such a case.
For this reason, make sure that L Alarm Value and H Alarm Value are set to different
values.
5.3 Forcing
Forcing is the procedure for replacing a variable's current value with a force value. The
variable receives its current value from a physical input, communication or a logic
operation. If the variable is forced, its value does no longer depend on the process, but is
defined by the user.
Forcing is used for the following purposes:
 Testing the user program; especially under special circumstances or conditions that
cannot otherwise be tested.
 Simulating unavailable sensors in cases where the initial values are not appropriate.
WARNING
Use of forced values can disrupt the safety integrity!
 Forced value may lead to incorrect output values.
 Forcing prolongates the cycle time. This can cause the watchdog time to be
exceeded.
Forcing is only permitted after receiving consent from the test authority responsible
for the final system acceptance test.
When forcing values, the person in charge must take further technical and organizational
measures to ensure that the process is sufficiently monitored in terms of safety aspects.
HIMA recommends to set a time limit for the forcing procedure, see
5.3.1.
Forcing can operate at two levels:
 Global forcing: Global variables are forced for all applications.
 Local forcing: Values of local variables are forced for an individual user program.
5.3.1 Time Limits
Different time limits can be set for global or local forcing. Once the defined time has
expired, the controller stops forcing values.

HIMA HIMax Specifications

General

Brand	HIMA
Model	HIMax
Category	Control Systems
Language	English