SMC Networks HRR018-A-10 Series Operation Manual page 37

 Wiring of interface communication cable
Be sure to turn OFF the breaker of the facility power supply (the
user's machine power supply) before wiring.
 Connecting to PC
RS-485 cannot be directly connected to a normal PC. Use an RS-232C/RS485 converter which is
available on the market.
Be sure to follow the wiring procedure shown below for connecting multiple thermo-chillers.
 Configuration of connection
One thermo-chiller for one host computer, or multiple thermo-chillers for one host
computer.(31 thermo-chillers can be connected at maximum.)
Terminal
resistance
SD+ SD - SG
Master
HRR Series
1 9 5
SD+ SD - SG
This product This product
(first slave) (second slave)
Do not connect any wire to other PIN numbers.
Fig 3-7 Connection of RS-485
[Tips]
Both ends of the communication connection (the end nodes) need to be
connected to the host computer.
With or without the terminating resistor of this product can be set by the
operation display panel. Refer to "5.5.5 Communication setting menu"
Chapter 3 Transport and Setting Up
1 9 5
SD+ SD - SG SD+
This product
(31 slaves)
HRX-OM-W002
1 9 5
SD - SG
l
Termina resistance
120 ?
st
3.3 Installation
3-17