Emerson E2 Manuel D’Utilisation
The I/O Network
The RS485 Network and Hardware Setup
•
6
-
5
Emerson Retail Solutions supplies a wide variety of
24VAC transformers with varying sizes and either with or
without center taps. Table 6-2 shows the transformer sizes
and whether they are center-tapped or non-center-tapped.
without center taps. Table 6-2 shows the transformer sizes
and whether they are center-tapped or non-center-tapped.
Table 6-3 lists each board, the board’s rating, and whether
or not the board must use center-tapped power.
or not the board must use center-tapped power.
Table 6-2
- Transformers Compatible with I/O Network Boards
Xformer P/N
VA Rating
Input Voltage
Center Tap?
640-0041
50 VA
110 VAC
No
640-0042
50 VA
220 VAC
No
640-0056
56 VA
Multi-tap (120/208/240 VAC)
Yes
640-0050
75 VA
110 VAC
No
640-0045
75 VA
220 VAC
No
640-0080
80 VA
Multi-tap (120/208/240 VAC)
Yes
Table 6-3
- Device Power Requirements
Unit
Amps
VA
VAC
Center-
tapped?
16AI
0.25
5.0
24
Yes
8RO/SMT
0.75
15.0
24
Yes
4AO
0.5
10.0
24
Yes
8DO
1.5
18
24
Yes
8IO/ARTC
0.75
18
24
No
IRLDS
N/A
N/A
120/240
N/A
RLDS
N/A
N/A
120/240
N/A
MultiFlex
ESR
3.3
80
24
Yes
MultiFlex
16
0.25
6
24
Yes
MultiFlex
88, 88AO,
168, and
168AO
0.75
15
24
No
MultiFlex
1616L,
1616LAO,
1616LDO
1.0
20
24
No
To select a power transformer for a board or a series of
boards:
1.
Determine what the total VA is for the boards
that will be powered by the transformer
that will be powered by the transformer
(see Table 6-3).
Example: Two MultiFlex 168AOs (15 VA
each), and one 8DO (18 VA) boards are to
be powered by one transformer. The total
VA is:
each), and one 8DO (18 VA) boards are to
be powered by one transformer. The total
VA is:
2
15VA
1
18VA
+
48VA
=
2.
Use a transformer that has a power rating
higher than the total calculated VA
higher than the total calculated VA
Example: For boards totalling 48VA, a 56VA trans-
former is sufficient, since 56VA is greater than 48VA.
I/O Board Transformers should be located within 10
feet of the board it is powering, preferably within the
board enclosure.
board enclosure.
6.1.9.1
Wiring Types
For powering I/O boards, use only the listed wire types
from Table 6-4. Three-conductor non-shielded cables are
the recommended wire for connecting between the center
tapped transformer and the I/O boards. The third conduc-
tor should be connected to earth ground. If boards use a
center-tapped transformer, also connect the center tap to
the earth grounded third conductor.
the recommended wire for connecting between the center
tapped transformer and the I/O boards. The third conduc-
tor should be connected to earth ground. If boards use a
center-tapped transformer, also connect the center tap to
the earth grounded third conductor.
Table 6-4
- Power Wiring Types
Power Wiring Types
14 AWG
Belden 9495
18 AWG
Belden 9493
The wire length from the transformer and the number
of boards connected to the same wire determines the type
wire gauge used. In most cases, the distance between the I/
O boards and the transformer that supplies power to them
is not enough to be concerned with. But it is very import-
ant not exceed this maximum wire length or the boards
will malfunction.
wire gauge used. In most cases, the distance between the I/
O boards and the transformer that supplies power to them
is not enough to be concerned with. But it is very import-
ant not exceed this maximum wire length or the boards
will malfunction.