1 - 5
1 Communications Methods
E5@C Digital Temperature Controllers Communications Manual (H175)
1-1 Overview of Communica-
tions Methods
1
1-1-5 Wiring
RS-485
• The RS-485 connection can be either one-to-one or one-to-N. Up to 32 units including the host
can be connected in a one-to-N system.
• The total cable length is 500 m max.
• Use shielded twisted-pair cable.
For detailed wiring specifications, refer to Precautions for Safe Use on page 7.
E5CC/EC/AC
1-1-5 Wiring
RS-485
14
13
RS-485
6.8 V
TX
RX
14
13
FG
−
+
SG
A (−)
B (+)
A (−)
B (+)
120 Ω
(1/2 W)
Abbreviation
Pin
Abbreviation
Specify both ends of the transmission path including the host
as the end node (that is, connect terminating resistance to both
ends). Use a terminating resistance of at least 54 Ω.
Host
E5CC/EC/AC
E5CC/EC/AC
End node
RS-485
Shield
Shield
Terminating
resistance
Use 120 Ω (1/2 W)
terminating resistance.
A < B: "1" Mark
A > B: "0" Space
Communications
transceiver
Pin
Abbreviation