Controller functions
Page 38
RES-445
The ACTUAL temperature shows whether the
heatsealing band is heated up to the preheating
temperature correctly, providing the display is in the
home position.
Please note the following if the "PREHEAT"
function is used and the temperature is selected via
the analog input at terminals 20+23:
The voltage at the analog input is valid for the
preheating temperature and the heatsealing
temperature. Preheating cannot be activated with the
"PREHEAT" signal in conjunction with the analog input.
If this function is used, the preheating temperature
must be set by altering the voltage value at the analog
input. The "START" signal is always activated for this
purpose (the "PREHEAT" signal is deactivated).
The timing sequence is shown in the diagram below:
10.11
"RESET" signal
The RESISTRON temperature controller RES-445 can
be reset by means of an external "RESET" signal at
terminals 20+26.
As a result:
• A heatsealing cycle is aborted if one is in progress
• No more measuring impulses are generated
• An alarm signal is reset if one is present
The "AUTOCAL" function is not aborted if the "RESET"
signal is activated while it is still executing.
The controller executes an internal
initialization for approximately 500ms after
the "RESET" signal is deactivated. The next
heatsealing process cannot be started until it has
finished.
If a contactor K2 is used to deactivate the
control loop
(
!
!
!
!
),
it must be energized again 50ms at the
latest after the "RESET" signal is deactivated. If it is
energized too late, an alarm signal will be output by
the controller.
10.12
"Temperature OK" signal
The RES-445 checks whether the ACTUAL
temperature is within a settable tolerance band ("OK"
window) on either side of the set temperature. The
lower (
) and upper (
) limits of the
tolerance band can be changed independently of one
another by means of steps 24+25 in the Configuration
menu.
"START"
signal
ACTUAL
temp.
Voltage at
anal. input
24VDC
T
2
T
1
T
1
= Preheating temperature (corresponds to
U
1
)
t
t
t
0
0
0
U
2
U
1
RES-445
max. 6mA
26
20
RESET
+
-
GND
24VDC
RESET
>0.1s
HIGH:
≥
12VDC
LOW:
≤
2VDC
!
!
∆ϑ
lower
∆ϑ
upper
