User Manual

1.5.7 Using a RS-485 of 7522A (D)
7522A
16
15
TXD3
+
TXD3
-
7000
m
odu
l
e
D2+
GN
D
+
VS
D2
-
Ext. GND
Ex
t.
24
V
7
8
9
1
0
Note:
• The RS-485 interface can directly drive 256 sets of 7000 modules without a
repeater
7521/2/2A/3/4/7 Series Hardware User’s Manual, Ver. 1.5 Sep/2002, 7Mh-001-15 -----38