Campbell Scientific MD9 Coax Multidrop Interface - Manual (Page 19)

D-1
Appendix D. SC532A
The SC532A differs from the SC532 in three ways:
1. Provides 12 V on PERIPHERAL Port pin 8
2. “PROGRAM” mode
3. Jack on SC532A POWER input
The SC532A supplies 12 VDC via PERIPHERAL connector pin 8 for the
purpose of powering 12 V peripherals.
The SC532A’s internal jumper selects “SC532” or “PROG” mode. For the
MD9 leave the jumper in the factory default position of “SC532.” “PROG” is
a special mode for satellite transmitters only.
The SC532A has a POWER jack allowing convenient replacement in the event
of AC adapter failure (see CAUTION below). The jack also facilitates
operating the SC532A from datalogger power at remote sites by using optional
field cable (item number 14020) in place of the AC adapter. Simply plug the
cable’s DB9 connector into the datalogger’s CS I/O port for 12 V power. If
you have an earlier datalogger lacking 12 V on CS I/O port pin 8 (DVM test
between paper-clip inserted in pin 8 and GND) the field cable can be modified
to connect to the datalogger’s power terminals as follows:
1. Unplug field cable from datalogger and SC532A.
2. Cut off DB9 connector.
3. Remove cable sheath exposing positive (RED) wire and negative
(BLACK) wire 2 inches back.
4. Strip ¼ inch of insulation from each wire and tin ends.
5. Connect RED wire to datalogger “12 V” and BLACK wire to datalogger
power ground terminal. The correct barrel connector polarity is (+) on the
inner bore and (
−) on the outer sleeve.
The MD9 requires that a minimum of 6 VDC @ 90 mA be supplied to the
SC532A POWER jack from AC adapter or field cable. The maximum voltage
that can be safely applied to the SC532A POWER jack is 17 VDC.
Before plugging the power connector into the SC532A, if
you have 1) cut off optional field cable’s DB9, 2) replaced
the factory AC adapter, or 3) built your own dc power
cable, make sure that the voltage polarity is correct on the
barrel connector. Application of REVERSED POLARITY
power to the SC532A can damage the SC532A,
datalogger, and peripheral (not covered under warranty)!
Barrel connector inner bore (+)
Barrel connector outer sleeve (
−
)
The maximum POWER input voltage is 17 VDC!
CAUTION