Rs-485 multi-drop connection, Rx tx – SATEC PM175 Manual User Manual
Page 31
Chapter 2 Installation
Communications Connections
Series PM175 Powermeters
31
UP TO 32 POWERMETERS
CABLE MAXIMUM LENGTH 1000M
RS485
RS232
RS485/422-232
+
SHLD
-
CONVERTER
SHLD
SHLD
SHLD
R t
RS-485 MULTI-DROP CONNECTION
2
PM172-N
R t 1
MASTER
R
S
-2
3
2
RXD
T
X
D
T
X
E
N
A
B
L
E
RXD
R
S
-4
2
2
/
R
S
-4
8
5
T
X
D
P
O
W
E
R
S
U
P
P
L
Y
COMMUNICATION CONVERTER
N
L
P
O
W
E
R
-
+
-
+
-
+
t1,
R
t
R 2=200-500 Ohm, 0.5W
2 (1)
2 (2)
PM172-N
2 (32)
PM172-N
Figure 2-33 COM2: RS-485 2 Wire Connection
-
4-20mA
9
8
COM.1 :
ATTENTION
Devices
Static-Sensitive
Static-Safe
Workstations
Handle Only at
POWER SUPPLY
RS-422/RS-485
16
+RX
COM.2
COM.1
11
V
15
13 14
6
9
N
1
5
-TX
+TX
-RX
V
MODEM
PROFIBUS
ETHERNET
RS-232/422/485 STANDARD
3
17
12
L/+
N/- 10
ANALOG IN/OUT :
0-1mA
0-20mA
V
-+1mA
LOW DC
N
(24) 18-36VDC
(48) 36-72VDC
S
2
(12) 10-16VDC
+
7
3
4 WIRE CONNECTION
RS-485/422 COMMUNICATION PORT
TO COMMUNICATION
SYSTEM
_
+
+
_
Rx
Tx
Figure 2-34 COM2: RS-422/485 4 Wire Connection