Campbell AVW200 series, Instruction Manual

Page: 108 / 112

Appendix I. Using MD485 Multidrop Modems with AVW200 Interfaces
Connect at one
end only to
chassis GND.
(-)
(+)
(-)
(+)
FIGURE I-5. MD485-to-MD485 Connections and Grounding
I.2.3 MD485 to AVW200
The 18663 Null Modem Cable is used to connect an MD485 with an AVW200.
One end of the null modem cable attaches to the RS-232 port on the MD485,
and the other end attaches to the RS-232 port on the AVW200 (see Figure I-4).
I.2.4 Multiplexer Connections
Multiplexers can be used in this configuration but the AVW200 has to control
the multiplexers. Refer to Section 4.5.1 for information on connecting the
multiplexers.
I.3 Programming
An AVW200() instruction is entered for each AVW200. The ComPort
parameter needs to be ComRS232.
I.3.1 Example Program
The example is for a network that looks like the following:
18663 Null Modem Cable
CABLE2TP Cable
AVW200 with
PakBus Address: 1 CR1000 MD485 MD485
AVW200 with
PakBus Address; 5
MD485
I-4