BusWorks
Model 903MB/902MB/901MB Network I/O Module User’s Manual Digital I/O
___________________________________________________________________________________________
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SERIES 901MB/902MB/903MB SIP
PULLUP RESISTOR SOCKET LOCATION
CAUTION: HANDLE CIRCUIT
USING ESD-SAFE PROCEDURES.
WHEN REPLACING COVER,
ALIGN ALL PINS, THEN SNAP
TOGETHER IN SEQUENCE
TO SECURE COVER.
USE SMALL SCREW DRIVER
TO PRY OFF SIDE COVER.
COVER IS HELD IN PLACE
WITH EIGHT SNAP PINS.
EACH PORT HAS A SIP RESISTOR
LOCATED AS SHOWN AT RIGHT.
SIP RESISTORS PULL-UP THE I/O
CHANNEL TO THE EXC SUPPLY.
SIPS ARE INSTALLED IN SOCKETS
X6, X7, AND X8.
PORT 0 SIP = R2 INSTALLED IN X6
PORT 1 SIP = R7 INSTALLED IN X7
PORT 2 SIP = R11 INSTALLED IN X8
THE SIP IS AN ISOLATED RESISTOR
NETWORK OF 4 ELEMENTS.
FACTORY SIP VALUE IS 5.6K OHMS.
POWER IS 0.5W PER ELEMENT.
THE EVEN-NUMBERED PINS OF
THE SOCKETS ARE TIED TO THE
PORT EXCITATION TERMINAL.
WHEN REPLACING SIPS OR
CHANGING VALUES, WATCH
THAT POWER DISSIPATION
DOES NOT EXCEED SIP RATING.
ST
Acromag
RUN
5.6K x4 ISOLATED
0.5W RESISTORS
RESISTOR
NETWORK
BOURNS 4308H-102-562
OR EQUIVALENT
SOCKET
D
IGIT
AL C
H
AN
N
ELS
7
9
11
R
6
8
10
2
3
DFT
0
1
4
5
PORT 0
CH0 CH1 CH2
4
5
6
7
8
R2
5
1 2
PORT 2
CH11
CH9
R11
CH10
4
3
X8
CH8
8
7
6
R7
2 1
3
X6
CH3
PORT 1
CH5 CH6
CH4
4
5
6
7
8
CH7
3 2 1
X7
RTN
PORT 2
(CH8-11)
TB4
EXC+
TB3
901MB/902MB/903MB SHOWN
WITH SIDE COVER REMOVED
EXC+
TB1
PORT 0
(CH0-3)
EXC+
RTN
TB2
PORT 1
(CH4-7)
RTN
4501-811A
Tx
D
D
D D
T
B
1
T
B
4
46
13
IN
0
+
44
O
U
T
2
43
16
IN
1
-
41
O
U
T
0
21
36
C
O
M
D
24
IN
2
-
33
D
T
B
1
12
C
H
0
45
C
H
1
1
15
C
H
3
42
C
H
8
TB2
T
B
2
21
E
X
C
2
23
C
H
5
34
D
24
26
R
T
N
31
COM
TB4
PWR
D
B
A
TB3
TB4
PWR
D
TB3
RS232
PORT
COM
11 12
CJC-0
45
R
T
N
O
U
T
3
TB1
15
IN
1
+
T
B
2
42
O
U
T
1
T
B
3
COM
TB2
23
26
25
IN
2
+
IN
3
+
IN
3
-
INPUTS 2,3
34
31
32
TB1
11
14
13
E
X
C
1
C
H
1
C
H
2
46
44 43
C
H
9
C
H
1
0
R
T
N
22
16
C
H
4
R
T
N
36 35
41
T
B
4
C
O
M
C
O
M
E
X
C
3
COM
25
C
H
7
C
H
6
32
33
T
B
3
D
Rx
RS485
DIGITAL OUTPUTS
DIGITAL I/O
RS485
CONNECT TO AC POWER
PERSONAL COMPUTER
MASTER -
SET BAUD RATE
OPTIONAL 120 OHM
TERMINATION RESISTOR
SET BAUD RATE
AND PARITY
14
22
IN
0
-
CJC-1
INPUTS 0,1
MODEL 924MB-0900
SET BAUD RATE, PARITY,
AND ADDRESS
35
R
T
N
C
O
M
CONNECT
POWER
4501-805B
DIGITAL IN or OUT
DIGITAL IN or OUT
MODEL 906MB-0900
SET BAUD RATE, PARITY,
AND ADDRESS
CONNECT
POWER
PC RUNNING
MODBUS
APPLICATION
SOFTWARE
ANY RS232-TO-RS485 CONVERTER
(ACROMAG MODEL 4SCC-TTM-X SHOWN)
RS485 NETWORK - HALF DUPLEX
TO ADDITIONAL
MODULES OR
OTHER RS485
NETWORK DEVICES
SEE NOTE REGARDING PORT COMMON AND EARTH GROUND CONNECTIONS.
SERIES 9XXMB NETWORK CONNECTIONS
NOTE (EARTH GROUND): PORT COMMONS ARE SHOWN CONNECTING VIA A THIRD
WIRE. A CONNECTION TO EARTH GROUND SHOULD ALSO BE PROVIDED AT ONE
POINT ALONG THE NETWORK. THIS IS ACCEPTABLE FOR MODULES LOCATED IN
CLOSE PROXIMITY TO ONE ANOTHER, BUT NOT RECOMMENDED FOR MODULES
DISTRIBUTED OVER LONG DISTANCES.
PER EIA 485 STANDARD, IT IS GOOD PRACTICE TO INSTEAD CONNECT PORT
COMMON TO EARTH GROUND VIA A 0.5W, 100 OHM RESISTOR AT EACH POINT ALONG
THE NETWORK, PARTICULARLY FOR NETWORKS THAT PROVIDE MULTIPLE GROUND
CONNECTIONS DISTRIBUTED OVER LONG DISTANCES.
1 - 300 5 - 4800
2 - 600 6 - 9600
3 - 600 7 - 19.2K
4 - 2400 8 - 38.4K
POWER
BAUD
RATE
acromag
T
B
1
R
S
-2
3
2
C
A
C
I
N
P
U
T
C
O
M
T
B
2
R
S
-4
8
5
R
R
T
R
x
T
x
2
4
V
D
C
D
D
C
O
M
T
2
4
V
D
C
R
T
N
S1
232 >
485
7
6
5
4
3
2
1
8
RS485
FAULT
485 >
232
