Acromag ACC1000, Инструкция по эксплуатации

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Serial Communication Converters & Adapters
Instruction Manual
12
To configure a two-wire network set both of the 2 WIRE
switch positions to ON (up). For a four-wire network set
both of the 2 WIRE switches to OFF (down).
When the RS-422 switch position is ON (up) it is
configured for an RS-422 network. For RS-485
networks set the RS-422 switch to OFF (down).
The ECHO switch position allows the data being sent
from the RS-232 port to be echoed back into the
RS-232 port. In most networks, this is an undesired
effect and the ECHO switch would be OFF (down).
ACC1001 DIP Switch Settings
SW1 Switch Position ON Setting Function
1
Network Termination
Included (120 ohm)
2
2-Wire Network Mode
Connection (factory
setting)
3
2-Wire Network Mode
Connection (factory
setting)
4 RS-422 Mode
5 ECHO Mode
Figure 19. ACC1001 DIP Switch Settings Chart
Figure 20 shows an example configuration of a two-wire
network. Each device (e.g. APM765/VPM3000 meter)
connected to the same network must have a unique
address.
Figure 20. ACC1001 RS-485 Two-Wire Multi-Drop Wiring
Notes:
1. Termination resistors are optional and values
depend on the cable length and characteristic
impedance. Consult the cable manufacturer for
recommendations.
2. Refer to APMA7422 RS-485 Serial Adapter on
page 10 for further details.
3. Use shielded cable, twisted-pair plus ground.
Connect ground shield only at one location.
Connections
To power the ACC1001, connect 12 VDC to the
+12VDC and ground to the GND screw terminals from
the supplied 115 VAC/12 VDC adapter.
The ACC1001 may be configured for either a four-wire
or two-wire network.
Figure 21 details the wiring
connections from the ACC1001 to an RS-485 serial
device in a four-wire network.
ACC1001 to RS-485 Serial Device Four-Wire
Connections
ACC1001 Serial
Converter
RS-485 Serial Device
Figure 21. Connections for ACC1001 in a Four-Wire
Network
Figure 22 details the wiring connections from the
ACC1001 to an RS-485 serial device in a two-wire
network when the DIP switches on the ACC1001 have
been set to the “2-Wire Mode”.
ACC1001 to RS-485 Serial Device Two-Wire
Connections
ACC1001 Serial
Converter
RS-485 Serial Device
Figure 22. Connections for ACC1001 in a Two-Wire
Network
The ACC1001 internally connects the /DI to the /DO and
the DI to the DO when the DIP switches are set to “2-
Wire Mode”. Either the /DI or /DO could be used to
connect to /DATA and either the DI or DO could be used
to connect to DATA.
Two ACC1001 RS-232 to RS-485 Serial Converters
could be used as a serial extender to allow RS-232
serial devices to communicate over long distances.
This would allow an RS-232 device to operate up to
3,937' (1,200 m).