KEYENCE N-400 - Manual (Page 106)

Chapter 5 Multi-Head Mode Control Procedure
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5
5.6 Communication Time
The following is the operation timing chart for “Single label” reading in multi-head
mode. This operation timing chart shows the case in which only one BL series
succeeded in reading bar code data. When several BL series simultaneously read
bar code data, the communication time may be longer than the following data.
Reading start delay time (F)
When the trigger input connected to the N-400 is turned ON in multi-head mode,
the N-400 sends the “Reading start (LON)” command to all connected units.
Therefore, the start of the BL series’ reading operations is delayed by the time
duration until the command transmission to all the BL series is completed.
The communication time required to send the reading start command to one BL
series is as follows:
When the number of connected BL series is “n”, the communication time is
calculated as follows:
F = D x n * n = Number of connected BL series
Serial output maximum delay time (G)
The serial output maximum delay time is the maximum delay time until the N-400
sends bar code data to the host computer after the BL series reads the data.
When the RS-485 communication baud rate is 38400 bps:
Baud rate (RS-485) Reading start delay time (D)
9600 bps 31 ms
38400 bps 13.5 ms
Serial output maximum delay time (G)
Number of data Number of data Number of data
digits: 10 digits: 20 digits: 32
2 96 ms 106 ms 116 ms
5 258 ms 268 ms 278 ms
10 528 ms 538 ms 548 ms
20 1,068 ms 1,078 ms 1,088 ms
31 1,662 ms 1,672 ms 1,682 ms
Number of
connected BL
series
F
F
H
G
I
Trigger input to
the N-400
Reading operation
N-400 <-> Host
computer (RS-232C)
Reading starts. The BL series read
bar code data.