KEYENCE N-400 - Manual (Page 105)

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Chapter 5 Multi-Head Mode Control Procedure
5
5.5 Interference Suppression Function
In multi-head mode, the BL series’ light sources (laser beams) are usually turned
ON simultaneously.
If the BL series are mounted close to each other, the laser beam emitted from one
unit enters the receiver of another unit, causing mutual interference. This may
result in a reading error or unstable reading. (Laser beams in close proximity often
cause interference.)
The interference suppression function allows each BL series’ laser beam to be
turned ON sequentially starting at the unit with the smallest ID number. Therefore,
the connected BL series do not simultaneously emit a laser beam. This function
prevents the laser beams from interfering with each other, ensuring stable read-
ings.
The differences in operation depending on the reading mode and the trigger input
signal type are the same as those in normal multihead mode.
- You can change the laser ON time (A) of each BL series by changing the BL
series’ setting. When (A) is prolonged, the reading operation is stabilized, but it
is not applicable for a high-speed line. Conversely, when (A) is reduced, the
reading operation is applicable for a high-speed line, but the reading stability
may decrease.
Note: The interference suppression function prolongs the time duration that each
BL series' light source is OFF. Therefore, reading may be impossible, when the
scan time is extremely short (for example, when the BL series cans bar codes on a
high -speed line).
A
A
A
• • •
• • •
• • •
Trigger input
Light source of
BL series with
ID No. 1
Light source of
BL series with
ID No. 2
Light source of
BL series with
ID No. 3