Micromod MOD: MODCELL Multiloop Processor 2002N Model C and Associated Hardware - Manual (Page 51)

MODCELL Multiloop Processor
ELECTRICAL CONNECTIONS
3.7 2020N REMOTE I/O INTERFACE CONNECTIONS (RIO)
Make remote I/O interface connections as shown in Figure 3-15. One remote I/O interface
module is required for each remote I/O network. Specifications are:
REMOTE I/O INTERFACE RS485 SERIAL NETWORK
Bus Master . . . . . . . . . . . 2020N Remote I/O Interface Module (end of bus)
Bus Slaves . . . . . . . . . . . . Remote I/O Digital Modules
Maximum Length . . . . . . . 500 meters (1600 feet)
Baud rate . . . . . . . . . . . . . 187.5K
Max addresses . . . . . . . . . 32 (31 slaves + 1 RIO master at address 0)
Termination . . . . . . . . . . . 120 ohm resistor is required across the two conductors
at each end of the cable (2 shipped with RIO module)
Shield . . . . . . . . . . . . . . . Required over 50 meters (160 feet)
REMOTE I/O INTERFACE CABLE
Indoor use . . . . . . . . . . . . Beldon #9182
Indoor plenum use . . . . . . Beldon #89182
Underground use . . . . . . . Beldon #9815 twisted twinax
Outdoors above ground use NOT recommended
Wiring . . . . . . . . . . . . . . . Use same cable type throughout network. Avoid
interruptions (wire to same terminals if necessary).
Do not wire through terminal blocks.
Figure 3-1 4 . Typical Interface Circuit for 2020N Remote I/O Interface Module (RIO)
**
MASTER
BUS1
S1
BASE INSTRUMENT UPPER
TERMINAL
HOUSING
2020N REMOTE I/O
INTERFACE MODULE
(Locations 1 & 2)
2 2
1
BUS2
BUS1
S2
13
14 2
1
DATA
Processor
SEL
CLK
GND
+5V dc 3
6
4
7
5
1
RS485
17
+5V dc
15
12 nF
class Y*
BUS2
1
2
Shield
3 18
Remote Unit
BUS1
BUS2
1
2
Shield
3 18
Remote Unit
120 Ohm
1/4 W
Reserved
* Connect capacitor to grounded cabinet
when noisy elements are in the area.
Otherwise, shield terminal can be used.
Class Y capacitor rated for use between
power line and ground.
** CAUTION
DO NOT connect RS485 bus to these
terminals. RIO module will be
damaged.
Note: RIO module is opto-isolated from
all units
SH1 *
120
ohm
1/4 W
4 5