Controller functions
RES-407
Page 27
observed extremely effectively and interpreted
accordingly. The same applies if mutual interference
occurs between several neighboring control loops.
If an alarm is signaled, this analog output is
used to display a selective error message
(
ª
ª
ª
ª
section 10.13 "Error messages" on page 32).
10.4
Automatic zero calibration
(AUTOCAL)
Owing to the automatic zero calibration (AUTOCAL)
function, there is no need to adjust the zero point man-
ually on the controller. This function matches the con-
troller to the current and voltage signals that are pre-
sent in the system. The zero point is calibrated in the
factory to the initial temperature (ambient temperature,
20°C).
Variable initial temperature:
On controllers manufactured as of April 2005, the initial
temperature for the "AUTOCAL" function can be set in
the 0…+40°C range in the visualization software
(
ª
section 10.11 "Diagnostic interface/visualization
software (as of April 2005)" on page 31). This setting is
remembered if the controller is switched off and then on
again.
As of SW Revision 107, the "External calibration tem-
perature" setting can also be selected in the visualiza-
tion software. The initial temperature for this setting can
be specified in the +3…+40°C range via the analog
input (terminals 16+14) (
ª
setting (set point selection)" on page 25). The value
selected at the analog input must be present when the
"AUTOCAL" function is activated.
If the specified temperature is too high (greater than
40°C) or if the selected value varies, an error message
appears (error codes 115 and 116;
ª
The "AUTOCAL" function is activated by means of a
24VDC pulse at terminals 5+14.
The automatic calibration process takes around
10…15seconds. The heatsealing band is not heated
during this process.
The yellow LED on the front panel lights up when the
"AUTOCAL" function is active. The actual value output
(terminals 14+17) is 0…3°C (corresponds to app.
0 VDC).
If the temperature of the heatsealing band varies on
controllers manufactured as of April 2005, the
"AUTOCAL" function is executed a maximum of three
times. If the function still cannot be terminated
successfully, an error message appears
(
ª
section 10.13 "Error messages" on page 32).
You should always wait for the heatsealing
band and the bar to cool down (to ambient
temperature) before activating the "AUTOCAL"
function.
Reasons for disabled "AUTOCAL" function:
1. The "AUTOCAL" function cannot be activated until
10seconds after the controller is switched on. If you
attempt to activate it sooner, it will not work.
2. The "AUTOCAL" function cannot be not activated if
the heatsealing band cools down at a rate of more
than 0.1K/s. If the control signal is activated, the
function is executed automatically providing the
cooling rate has fallen below the above-mentioned
value.
!
RES-407
max. 6mA
5
14
AUTOCAL
+
-
GND
24VDC
AUTOCAL
0.1…5s
HIGH:
≥
12VDC
LOW:
≤
2VDC
13
!
