Campbell CH201, Product Manual

Page: 35 / 44

Table 7-4: SDI-12 extended commands and responses
SDI-12 Command Description Response
a
XT
nn.nn
!
Where:
a = CH201 SDI-12 address
nn.nn = temperature in °C
Overrides the internal temperature
measurement for 15 minutes (or until
cancel
l
ed by a temperature restore
command). Useful for entering the
temperature of a remote battery.
Temperature range is –40.00 to
100.00 °C.
a
OK
a
XTR!
Where:
a = CH201 SDI-12 address
Restore temperature measurement to
internal CH201 measurement.
a OK
a
XC
nn.n
!
Where:
a = CH201 SDI-12 address
nn.n = battery capacity in Ah
Enter battery capacity in Ah. Used to
charge the battery correctly. Must be
non-zero to use the quicker dual-rate
charging scheme.
a
OK
a
XRQ!
Where:
a = CH201 SDI-12 address
Sets Qloss to zero. If not used, the
CH201 will automatically set Qloss to
zero after trying to cycle charge a
battery for eight hours or more.
a
OK
Downloadable example programs using these extended commands are available at
www.campbellsci.
eu
/downloads/ch201-program-examples .
7.3.1.2 CRBasic programming
The CRBasic instruction
SDI12Recorder()
is used to program a data logger to communicate
with the CH201 using SDI-12. Refer to the CRBasic help for information about this instruction.
Downloadable SDI-12 example programs are available at
www.campbellsci.
eu
/downloads/ch201-program-examples .
7.3.2 RS-232 communications
The CH201 can use RS-232 to communicate directly with a Campbell Scientific data logger, or it
can communicate with a computer through an A200 module. The following table shows the
wiring for both connections.
CH201 12V Charging Regulator 25