SMC Networks HRS090-A, Operation Manual

Page: 45 / 196

HRX-OM-S004
Chapter 3 Transport and Setting Up
HRS Series
3.3
Installation
3-25
3.3.8 RS-485 communication wiring
Serial communication RS-485, operation start/stop, setting and reading of
circulating fluid temperature, and reading of alarm condition can be done by
remote control.
Refer to the Operation Manual Communication Function for more details.
„ Wiring of interface communication cable
z
Connecting to PC
RS-485 cannot be directly connected to a normal PC. Use a RS-232C/RS485 converter which is
available on the market.
Be sure to follow the wiring procedure shown below for connecting multiple thermo-chillers.
z
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.)
1
SD+
5
SG
9
SD-
SD+
SD- SG
Terminal
resistance
Master This product
(first slave)
1
SD+
5
SG
9
SD-
This product
（ second slave ）
1
SD+
5
SG
9
SD-
This product
（ 31
st
slaves ）
Terminal
resistance120
Ω
Fig. 3-14 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 (120 Ω ) of this product can be set by
the operation display panel. Refer to “5.21 Communication function”.
Be sure to turn OFF the breaker of the facility power supply (the user's
machine power supply) before wiring.