DFE WebHandler 3 Instruction Manual page 40

6. Setup for Tension Limit Switch
The TLS feature is typically used to provide an alarm when web tension exceeds or drops below user
determined levels. It can also be configured to provide an alarm when tension is within a specified
operating range. When a TLS condition occurs, the controller provides a visual alarm indication on the
display and activates a set of relay contacts which the user can use within his machine. The TLS
condition can also be used to disable controller output (turn Tension Off). There are four TLS modes
available to TLS Lo and TLS Hi independently: Momentary; Latched; Momentary Raw; and Latched
Raw. These are described below.
In Momentary mode, a TLS alarm is triggered when the tension is below (for TLS Lo) or above (for
TLS Hi) the corresponding setpoint. If the tension goes back within the normal range, the TLS alarm is
cleared. In this mode, TLS is not armed until the tension has entered the non-alarm range. This is useful
when your process might not produce reliable tension readings until the process is up and running, and
you want the momentary alarm condition to disable the machine, such as for a web break.
In Momentary Raw mode, a TLS alarm is triggered when the tension is below (for TLS Lo) or above
(for TLS Hi) the corresponding setpoint. If the tension goes back within the normal range, the TLS alarm
is cleared. The difference between this mode and standard Momentary mode, is that the alarm is triggered
even if the tension has never been brought into the non-alarm range. This mode can be useful if your
process stays under tension even when the controller is not powered up or enabled, but you want
indication that the tension is not within desired limits.
In Latched mode, a TLS alarm is triggered when the tension is below (for TLS Lo) or above (for TLS
Hi) the corresponding setpoint. If the tension goes back within the normal range, the TLS alarm is not
cleared, and remains active until the operator clears it by pressing the EXIT key on the front panel. Note
that in this mode, TLS is not armed until the tension has been entered the non-alarm range. This is useful
when your process might not produce reliable tension readings until the process is up and running, and
you want a maintained alarm condition to disable the machine and provide positive indication of what
caused the shut down.
In Latched Raw mode, a TLS alarm is triggered when the tension is below (for TLS Lo) or above (for
TLS Hi) the corresponding setpoint. If the tension goes back within the normal range, the TLS alarm is
not cleared, and remains active until the operator clears it by pressing the EXIT key on the front panel.
The difference between this mode and standard Momentary mode, is that the alarm is triggered even if
the tension has never been brought into the non-alarm range.
In any mode, a user determined delay is available to eliminate false triggering. Once configured, TLS can
be turned Off while maintaining the trip points so that it can be used only when needed.
If relay output is desired, make the connection as follows:
Figure 35 - TENSION LIMIT SWITCH OUTPUT CONNECTIONS
You must then configure operation of the TLS functions according to your application. TLS Lo and Hi
Set TLS Lo Mode
are configured independently from each other. In the Setup Menus, navigate to (and/or
Set TLS Hi Mode Momentary, Momentary Raw, Latched, or Latched Raw
). Choose operation, as
described above.
SetTLS Lo Setpt SetTLS Hi
Then the TLS Lo and Hi set-points can be entered in the functions and
Setpt
, respectively. The set-points are entered in the same units of measure as your measured Tension.
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