Emerson 851-1000, Инструкция по установке и эксплуатации

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6 • PMAC II I&O Manual 026-1501 Rev
6
2.2. 8DO Board Configuration
(Standard PMAC II Only)
The 8DO (Digital Output) Expansion Board, supplied
with the PMAC II panel, and shown in Figure 2-8 , is used
to connect refrigeration and environmental control compo-
nents, which must be controlled by digital output, to an RS-
485 I/O Network. An adjustable dip switch, rotary dials,
and jumpers are used to configure the 8DO board to fit a va-
riety of applications. Table 2-1 provides the required infor-
mation to configure the 8DO board to allow
communication between the RMCC, E2 or BEC, the
PMAC II panel, and the case heaters.
2.2.1. Digital Outputs
The 8DO Expansion Board uses eight digital outputs,
which modulate at a programmable frequency regulated by
a signal sent from the controller via the I/O Network.
Each of the eight outputs is designed to drive a solid-
state device, and is capable of supplying approximately
150 mA at +12 volts (unregulated). Each output has current
limiting circuitry to prevent damage when short-circuited.
When an output is overloaded, the corresponding LED in-
dicator flashes quickly, indicating current limiting is in ef-
fect.
2.2.2. Fail-Safe Dip Switch
The fail-safe dip switch, S3, allows the user to provide
continuous voltage to the case heaters during network com-
munication loss. The fail-safe dip switches should always
remain in the UP position to ensure voltage is always pro-
vided to the case heaters. If the switches are set in the
DOWN position, no voltage will be sent to the heaters dur-
ing network communication loss.
2.2.3. Network Jumpers
The network jumpers—JU1, JU2, and JU3—define
whether the PMAC II 8DO board is the first or last board,
or a middle board on the RS-485 communication network.
Figure 2-8 - 8DO Board
NOTE: Connection of the PMAC II panel
8DO board must meet all networking require-
ments of the BEC, RMCC, or E2 controllers.
Table 2-1 defines the proper settings for the
PMAC II 8DO board. Refer to the controller’s installa-
tion and operation manual for further information.
Component Required
Setting
Action/Notes
Fail-Safe Dip
Switch (S3) Positions 1-4,
UP Position 5,
unused Provides continuous
12VDC to the PMAC
II relays during net-
work communica-
tion loss.
Rotary Dials
(S1)
(S2)
0
1
Addresses the PMAC
II 8DO board as the
#1 8DO board on the
RS-485 Network.
Jumpers
JU1
JU2
JU3
UP/DOWN
UP/DOWN
UP/DOWN
If the PMAC II 8DO
board is the last board
on the RS-485 Net-
work, set all three of
the jumpers UP. If the
board is in the middle
of the RS-485 Net-
work, set the jumpers
DOWN.
Network Connec-
tion Connect to
RS-485 Net-
work
Must “daisy-chain"
with other network
boards.
Table 2-1 - PMAC II 8DO Setup