Tension Zones; Examples Of Tension Zones - DFE STEADYWEB 6 Technical Reference Manual

1.1 GENERAL DESCRIPTION continued....
2. Tension Regulator
The second component is the tension regulator. The controller compares the measured tension to the Auto
setpoint value and adjusts an output signal to equalize the measured and desired tension. The regulator
function is performed by software and may be influenced by other signal inputs, such as web speed and roll
diameter, as dictated by operator-adjustable settings. Regulation is achieved with a PID (Proportional,
Integral, Derivative) based control loop with advanced capabilities such as roll diameter compensation and
web acceleration compensation.
3. Output Converter
The third component is the output stage, the signal from which is used to actuate a brake, clutch, or variable
speed DC or AC drive which in turn creates the actual web tension. The output stage is available in several
application-dependent versions. Standard in every controller is an isolated control output (adjustable range
within the limits of ± 10 Volts or 4-20 mA). Optionally, a 0-24VDC output stage may be included internal to the
controller to drive 24V devices drawing up to 2.5A. Higher current 0-24V devices may draw customer-
supplied power through the controller's terminals. Optional external output modules are available to drive
higher voltage electrical devices with 0 – 45/90 VDC @ 5 Amps and pneumatic devices with 2 – 75 psi.
WARNING:
The isolated output is designed to prevent ground loops and noise. It is not intended or approved for safety
isolation of hazardous voltages. Do not install unit where the isolated circuit and chassis ground are more than
.
40Vpk differential
WARNING:
AC versions of the SteadyWeb
damage and potential hazard, do not connect them across three phase lines or three phase circuits.

1.2 TENSION ZONES

Tension zones are created by driven or braked nip rolls, drag bars, braked unwind, driven unwind, or rewind
shafts, or anything else that can increase or decrease web tension. One of these elements is at each end of
every tension zone.
Many machines that process a continuous web have more than one tension zone. The SteadyWeb
can be used in all tension zones, when properly configured for the zone it will be used in. See Figure 2 for

examples of tension zones.

2
™
6 controller are designed for single phase AC operation only. To prevent product
Figure 2 - EXAMPLES OF TENSION ZONES
™
6 controller