KEYENCE BL-180 - Manual (Page 94)

Power Supply BL-U1
88
1.8 Wiring the RS-485 (multidrop link)
Multidrop link is a method to connect multiple BL series units to a single PC. See
P. 82 of this document for details. Use the terminal blocks SDA and SDB.
Twisted pair cable
• Up to 31 BL-U1 (BL series) units can be connected in multidrop link.
• The extended cable length must be within 1.2 km.
• Connect the BL-U1 (BL series) to a PC using a commercially available RS-
485/RS-232C convertor.
• For units between the RS-485 (those marked with * in the above figure), turn
ON the terminator.
You can turn the BL-U1 terminator on and off using DIP switch 5. For the ter-
minator of the RS-485/RS-232C convertor, see the instruction manual for the
convertor.
• Do not connect the RS-485 cable through the terminal block.
• Do not connect the multidrop link cables together with the power cable.
• Avoid connection including branch of the BL-U1 and RS-485/RS-232C conver-
tor as shown below.
SDA
SDB SDA
SDB SDA
SDB SD/RD+
SD/RD-
RS-232C
PC
*
*
BL-U1 BL-U1 BL-U1
RS-485/RS-232C convertor
GND SG SG SG
Twisted
Shielded cable
CAUTION
BL
BL BL Convertor
BL
BL BL Convertor * *
Not applicable
(Connection with branch)
Applicable
(Connection without branch)
Terminator ON