KEYENCE N-400 - Manual (Page 99)

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Chapter 5 Multi-Head Mode Control Procedure
5
5.2 Reading Operation in Multi-Head Mode
5.2.1 Difference in operation depending on reading mode
Multi-head mode can control several BL series like they are a single bar code
reader. The N-400 provides the “Level” and “Oneshot” trigger signal types, and the
“Single” label and “Multi” label reading modes.
“Single” label reading mode
The following timing chart shows the case in which three BL series are connected.
• In the “Single” label reading mode, a piece of data which was first read by any
of several BL series is sent to the host computer. (When any of the connected
BL series reads bar code data, all light sources of the other BL series are turned
OFF.) Therefore, several BL series can be operated like a single bar code
reader.
• If all of the connected BL series units cannot read bar code data while the
trigger input is ON, a read error code is output.
• Normally, the BL series sends data immediately after reading it. However, you
can set the data transmission timing so that data is sent after the trigger input is
turned OFF. (
➮ See p. 94.)
“Multi 1” label reading mode
The following timing chart shows the case in which three BL series are connected.
Reading
Timing 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
Communication
output
* A piece of data which was read
first is sent. * Read error
Reading
Reading
* Data is sent sequentially starting with
the earliest data. * Read error
Timing 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
Communication
output