KEYENCE N-400 - Manual (Page 28)

Chapter 2 Installation Procedure
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2
• The diagram on the previous page shows the connections to supply 24 VDC
power to the N-48 from the power supply connected to the N-400. In this case,
the 24 VDC power supply connected to the N-400 must have a capacity of at
least “140 mA (N-400 current consumption) + 260 mA (N-48 current consump-
tion) x n (Number of N48 units connected)”.
Example
When five N-48 units are connected:
140 mA + 260 mA x 5 = 1.44 A
Use a power supply with at least 1.44 A capacity.
Note: The RS-485 cable can be extended up to 1.2 km. With the power supply
cable, however, the 1.2 km extension is not guaranteed.
To extend the power supply cable as shown in the connection diagram on the
previous page, ensure that the power voltage supplied to all the N-48 units is within
the range of 24 VDC -20% to +10%.
• To connect a 24 VDC power supply to each N-48 unit, remove the 24 VDC
wiring shown in the previous page. To connect the power supply, use the follow-
ing cable.
Recommended RS-485 cable
• 0.75 mm 2 x 2 cores, sheilded
• Up to thirty-one N-48 (BL series) units can be connected in multi-drop link mode.
• The total extension length of the RS-485 cable must be within 1.2 km.
• Turn ON the equipment terminator (termination resistance: 100 Ω ) at both ends
of the RS-485 connection (marked with * in the figure above).
• Turn ON/OFF the N-48 terminator using the terminator switch. ( ➮ See p. 7.)
• Turn ON/OFF the N-400 terminator using the terminator switch. ( ➮ See p. 6.)
Note: Be sure not to connect the RS-485 cable using the terminal block.
Note 1: Do not place the RS-485 cable in the same conduit as a power cable.
Note 2: Do not branch the RS-485 connection as shown below.
N-48 N-48
N-48
N-400 N-48 N-48
N-48
N-400
*
*
* Terminator ON
Incorrect
(Connection with branch) C orrect
(Connection without branch)
Incorrect Correct