Control circuit
34
■
RS485 Communication Terminal
SP and SN terminals with the same names are internally connected respectively, so they can be used
for wiring multiple terminals.
Terminal
symbol
Terminal
name
Description
Electrical character-
istics
RS485 com-
munication
Serial
communi-
cation
SP
SN
RP
(CM1)
RS-485
terminal
for Modbus
communi-
cation
SP terminal: RS-485 differential (+) signal
SN terminal: RS-485 differential (-) signal
RP terminal: Connect to SP via tile terminating
resistor
CM1 terminal: Connect with the signal ground
of an external communication device.
(also used by FM terminal)
There are two SP terminals and SN terminals
each, which are connected internally.
Maximum baud rate is 115.2kbps.
Equipped with termi-
nating resistor
(120
Ω
)
Enable: Short RP-SN
Disable: Open RP-SN
(+) (-)
Control circuit terminal area
Modbus communication
RP
SN
SP
SN
SP
CM1
Connect CM1 to the SG
(signal ground) of an
external device.
When enabling the terminating
resistor, short RP-SN.