KEYENCE N-400 - Manual (Page 11)

Chapter 1 Overview of The N-400
1
■ Mutual-interference suppression function (in multi-head scan mode)
When several bar code readers are mounted close to each other, for example when
reading multi-stage labels as shown below, the units’ light sources (laser beams)
interfere with each other, affecting the reading stability.
The mutual-interference suppression function allows the BL series’ laser beams to
turn ON sequentially, thus suppressing the mutual interference to ensure stable
readings.
Since the laser beams turn ON sequentially, the duration of laser OFF time (when
each unit is not reading a bar code) becomes longer as the number of connected
units is increased. Therefore, the bar code readers may fail to read bar codes if the
line speed is set too fast.
■ PLC link function
In the multi-drop link mode or multi-head scan mode, the PLC link function enables
the BL series’ data to be sent to a PLC without a communication program. Using
this function, you can reduce the number of steps for a PLC program.
N-400
RS-485
N-48
or
BL-U1 RS-232C
Host
BL series
Sensor for
trigger input
N-400
To BL
•
•
•
•
•
•
No communication program is necessary,
because the N-400 stores the data read by
the BL series directly into the PLCs memory.
DM103
DM104
DM105
DM106 4
&30
&31
&32
3