Startup and operation
Version 1
RES-409
Page 27
The least significant identifier bit has a fixed value of 0 for receiving CAN messages:
The least significant bit has a fixed value of 1 for sending CAN messages. The identifier for CAN messages sent
by the RES-409, in other words, always has a value one higher than for received CAN messages.
9.2.7
DIP switches for activating the terminating resistance
The "Termination" DIP switch can be used to switch a terminating resistance of 150ohms between the two CAN
lines (CAN-L and CAN-H). This switch must be set to "ON" in order to activate the resistance.
9.3
Heatsealing band
9.3.1
General
The heatsealing band is a key component in the control loop, since it is both a heating element and a sensor. The
geometry of the heatsealing band is too complex to be discussed at length here. We shall therefore only refer to
a few of the most important physical and electrical properties.
The measuring principle applied for this system necessitates a heatsealing band alloy with a suitable temperature
coefficient TCR, i.e. one whose resistance increases as the temperature rises.
Too low a TCR leads to oscillation or uncontrolled heating.
If a heatsealing band with a higher TCR is used, the controller must be specially calibrated.
The first time the heatsealing band is heated to approximately 200…250°C, the standard alloy undergoes a once-
only resistance change (burn-in effect). The cold resistance of the heatsealing band is reduced by approximately
2…3%. However, this at first glance slight resistance change results in a zero point error of 20…30°C. The zero
point must therefore be corrected after a few heating cycles (
section 9.3.2 "Burning in the heatsealing band" on
page 27).
One very important design feature is the copper or silver-plating of the heatsealing band ends. Cold ends allow
the temperature to be controlled precisely and increase the life of the teflon coating and the heatsealing band.
An overheated or burned-out heatsealing band must no longer be used because the TCR has been
altered irreversibly.
9.3.2
Burning in the heatsealing band
If a new heatsealing band has been used, the zero point is first of all calibrated while the band is still cold by
activating the "AUTOCAL" function on the controller. When the "AUTOCAL" function has finished, the controller
outputs the preselected calibration temperature (default value: 20°C) as the ACTUAL temperature at the analog
actual value output as well as in the controller status. Adjust the set point to approximately 250°C and send a
"START" command with a heatup time of approximately 1 second (
section 10.3.2 "START / STOP command
"START" signal" on page 34). After cooling down again, the controller usually indicates a value less than 20°C.
Repeat the "AUTOCAL" function. The heatsealing band has now been burned in and the change in the alloying
properties stabilized.
ID.10 ID.9 ID.8 ID.7 ID.6
0
0
0
0
0
0
DIP.1 DIP.2 DIP.3 DIP.4 DIP.5
ID.10 ID.9 ID.8 ID.7 ID.6
0
0
0
0
0
1
DIP.1 DIP.2 DIP.3 DIP.4 DIP.5
!