Eriez Xtreme, Reference Manual

Page: 29 / 122

TACHOMETER INPUT
Applications having variable speed product flow and requiring automatic reject timing use this
input. A tachometer is used to allow the metal detector control to monitor product speed, and
reject according to the distance the product has traveled rather than according to elapsed time
since detection. (Note: a “Tachometer Fault” occurs if the input does not receive pulses from
the tachometer for a period of time, defined on the “Advanced Reject Settings” screen.)
REJECT INDEX
The metal detector can be used to scan and automatically reject packages. In this application a
reject index is used to sense the location of the package so it can be reliably rejected. The
device can be a mechanical switch, photo-eye, or any other device that is capable of precisely
locating the package.
REJECT CONFIRMATION
The reject confirmation input is used to monitor the function of the reject device. It is usually a
limit switch attached to the reject device that indicates it is functioning. For example, if you
were using a pusher bar, the reject confirmation switch would be wired to the reject confirmation
input and positioned in such a way that it closes as the pusher bar reaches maximum
extension.
REJECT RESET
The metal detector has four timers, one of which is a “Reject Timer” connected to the “Reject
Relay.” The Reject Timer has the option of being set to either manual or automatic reset mode.
Manual Reject Reset is typically used for a stop belt reject. When the Reject Timer is set to
manual reject reset and a rejection occurs, a password protected button will appear at the
bottom center of the screen to reset the metal detector. Another option is to wire a reject reset
button to one of the eight input connections to reset the timer. Typically a momentary push-
button switch is used for this purpose. The logic can be set to either NO or NC and the specific
input selected. When either manual reset is performed, the Reject Relay will be reset.
PRODUCT COUNTER
A photo-eye or limit switch can be used to detect and count each package that passes through
the metal detector. The product count is displayed on the Home screen. Note that a single
physical device (e.g. photo-eye) can be used for product counting and for the reject index; in
this case the photo-eye output should be connected to two inputs on the metal detector, one
configured as Reject Index, and another as Product Counter.
AIR PRESSURE FAILURE
This input configuration can be used to provide an “Air Pressure Failure” fault or warning when
the air supply is lost. Connect a pressure switch to the reject devices’ air supply, and configure
the input to be active when air pressure is less than the required value.
ELEC
27