= ALno
if the alarm output has to be active when the alarm is
active while it is deactivated when the alarm is not active.
= ALnc
if the alarm output has to be active when the alarm is not
active while it is deactivated when the alarm is active.
Enter group
“
]
Hb”
and program which output the alarm signal has
to address on parameter
“OHb
.
The functioning mode of the alarm is instead defined on par.
“HbF”
which can be set in the following way :
= 1
: The alarm is active when, with output 1rEG active, the current
measured by the input TAHB is lower than the value programmed
on par.
"IHbL"
.
= 2
: The alarm is active when, with output 1rEG not active, the cur-
rent measured by the input TAHB is higher than the value pro-
grammed on par.
"IHbH"
.
= 3
: The alarm is active when, with output 1rEG active, the current
measured by the input TAHB is lower than the value programmed
on par.
"IHbL"
or with output 1rEG not active, the current meas-
ured by the input TAHB is higher than the value programmed on
par.
"IHbH"
.
= 4
: The alarm is active when the current measured by the input
TAHB is lower than the value programmed on par.
"IHbL"
or the
measured current is higher than the value programmed on par.
"IHbH"
, independently by the state of the output 1.rEG.
On par. “IHbL” the value of the current normally absorbed by the
load when output 1.rEG is active has to be set, while on par. “IHbH”
the current normally absorbed by the load when output 1.rEG is not
active.
The programming of these parameters has to be carried out while
also considering the fluctuations of the net voltage to avoid
undesired alarms.
With regards to the hysteresis of the HB alarm, this is automatically
calculated by the instrument as 1% of the programmed thresholds.
During functioning it is possible to visualize the current measured
by the input TAHB when output 1rEG is activated, by pushing the
“DOWN” key and the current measured when output 1.rEG is deac-
tivated, by pushing the “DOWN” and “U” keys at the same time.
To exclude the Heater Break alarm it is enough to set “OHb” =
OFF.
Note :
The HB current measurement is valid if the output 1rEG is
activated (or deactivated) for 264 ms. at least.
This means that, if the cycle time (“tcr1”) is = 1 sec, the HB alarm is
able to intervene only when the output power is higher than 26,4%.
4.16 - LOOP BREAK ALARM FUNCTION
All the parameters referring to the Loop Break alarm function are
contained in the group
“
]
LbA”.
The Loop Break alarm is available on all the instruments, which
intervenes when, for any reason (short-circuit of a thermocouple,
thermocouple inversion, load interruption), the loop control is
interrupted.
First of all, it is necessary to establish to which output the alarm
has to correspond.
To do this it is necessary to set the parameter relative to the output
to be used (“O1F”, “O2F”, “O3F”, “O4F”, “O5F”, “O6F”) in the
groups
“
]
Out ”,
programming the parameter as :
= ALno
if the alarm output has to be ON when the alarm is active
while it is OFF when the alarm is not active.
= ALnc
if the alarm output has to be ON when the alarm is not
active while it is OFF when the alarm is active.
Enter group
“
]
LbA”
and program which output the alarm signal
has to be addressed to on par.
“OLbA”
.
The Loop Break alarm is activated if the output power remains at
the 100% of the value for the time programmed on par.
"LbAt"
(expressed in sec.).
To avoid false alarms, the value of this parameter has to be set
considering the time the plant takes to reach the Set point when
the measured value is a long distance from it (for example at the
plant start-up).
On alarm intervention, the instrument visualizes the message
“LbA”
and behaves as in the case of a measurement error giving a
power output as programmed on par.
“OPE”
(programmable in
the group
“
]
InP”)
.
To restore normal functioning after the alarm, select the control
mode “OFF” and then re-program the automatic control (“rEG”)
after checking the correct functioning of probe and drive.
To exclude the Loop Break alarm, set “OLbA” = OFF.
4.17 - FUNCTIONING OF KEY “U”
The function of key “U” can be set through par.
“USrb”
contained
in the group “
“
]
PAn”.
The parameter can be programmed as :
= noF
: no function
= tunE
: Pushing the key for 1 sec. at least, it is possible to
activate/deactivate Auto-tuning or Self-tuning
= OPLO
: Pushing the key for 1 sec. at least, it is possible to swap
from automatic control (rEG) to manual one (OPLO) and vice
versa.
= Aac
: Pushing the key for 1 sec. at least, it is possible to
acknowledge the alarm. (see par. 4.14)
= ASi
: Pushing the key for 1 sec. at least, it is possible to
acknowledge an active alarm (see par. 4.14)
= CHSP
: Pushing the key for 1 sec. at least, it is possible to select
one of the 4 pre-programmed Set Points on rotation.
= OFF
: Pushing the key for 1 sec. at least, it is possible to swap
from automatic control (rEG) to OFF control (OFF) and vice versa.
4.18 - DIGITAL INPUT
The instrument is equipped with 2 digital inputs whose function can
be set by the parameter
"diF"
contained in the group
“
]
InP”.
The parameter can be programmed as:
= noF
: the input does not carry out any function
= AaC
: By closing the contact connected to the digital input, it is
possible to reset a memorised alarm (see par. 4.14)
= ASi:
By closing the contact connected to the digital input, it is
possible to silence an active alarm (see par. 4.14)
=
HoLd
: By closing the contact connected to the digital input the
measurement taken at that moment is blocked (N.B.: not the
reading on the display, therefore the indication may stabilise itself
with a delay that is proportional to the measuring filter). With the
hold function turned on, the instrument carries out control
according to the memorised measurement. By opening the contact,
the instrument starts normal measurement acquisition once more.
= OFF
: When the instrument is in “rEG” status, by closing the
contact connected to the digital input, the instrument is placed in
OFF status. By reopening the contact, the instrument returns to the
automatic control status “rEG”.
= CHSP
: by closing and reopening the contact connected to the
digital input, it is possible to select one of the 4 memorised set
points in rotation.
= SP1.4
: The following combination of the connected contacts to
the two digital entries allows the activation of one of the 4
memorized set points.
SP4
on
on
SP3
on
off
SP2
off
on
SP1
off
off
SET POINT
DIG IN2
DIG IN1
The function can be activated using “nSP” = 4 , also, when it is acti-
vated, it disables the selection of the active set by the parameter
“SPAt” and by the key U.
= HE.Co
: by closing the contact connected to the digital input it is
possible to select as active the set point SP2 in “CooL” mode. Reo-
pening the contact is select as active the set point SP1 in “HEAt”
mode. This function is possible only when “nSP” = 2.
4.19 - RS 485 SERIAL INTERFACE
The instrument can be equipped with a RS 485 serial
communication interface, by means of which it is possible to
connect the regulator with a net to which other instruments
(regulators of PLC) are connected, all depending typically on a
personal computer used as plant supervisor. Using a personal
computer it is possible to acquire all the function information and to
program all the instrument’s configuration parameters. The
software protocol adopted for TLK94 is a MODBUS RTU type,
TECNOLOGIC spa - TLK 94
-OPERATING INSTRUCTIONS - Vr.01 - 01/10 - ISTR-MTLK94ENG1 - PAG. 11
