Campbell Scientific MD485 RS-485 Multidrop Interface - Manual (Page 11)

MD485 RS-485 Multidrop Interface
(-)
(+)
(-)
(+)
Connect at one
end only to
chassis GND.
FIGURE 3. RS-485 Connections and Grounding
3.4 Serial Cables
In an MD485 base station, a straight-through DB9M/DB9F RS-232 cable will
connect from the MD485’s RS-232 port to the PC COM port. This cable is
included with the MD485.
A remote MD485 normally uses the included SC12 cable to connect the
MD485’s CS I/O port to the datalogger’s CS I/O port.
A remote MD485 can be connected to a CR200(X)-series, CR800, CR850,
CR1000, CR3000, or CR5000’s RS-232 port with a null modem DB9M/DB9M
cable (CSI Item # 18663).
4. Quick Start
This section is intended to serve as a “primer” enabling you to quickly build a
simple system and see how it operates. This section describes in five steps
how to set up a pair of MD485s in a direct connect, point-to-point network.
We recommend that you do this before undertaking field installation.
For this system you will need the following hardware or the equivalent:
1. Two MD485s
2. Transformer (Item # 15966)
3. Serial cable for PC COM port to MD485 RS-232 port (included with
MD485)
4. SC12 cable (included with MD485)
5. CSI Datalogger (such as CR1000, CR3000, CR10X, or CR23X)
6. Field Power Cable (Item # 14291)
if older datalogger or wiring panel
doesn’t have 12 V on pin 8 of CS I/O port
7. CABLE2TP-L 2-twisted-pair cable with shield and Santoprene jacket
You will also need:
1. A PC with one available COM port
2. LoggerNet, PC400, or PC208W installed
5