Campbell Scientific CR200/CR200X-series Dataloggers - Manual (Page 124)

Section 11. Programming Resource Library
11.3 Multiple Switch Closure Measurements
Pulse channel P_SW detects switch closures but P_LL does not. In order to
detect more than one switch closure device, a 100kOhm pull-up resistor must be
connected between Battery+ and P_LL, C1, or C2. With the pull-up resistor in
place P_LL or the control port can detect a switch closure. In the following
example p. 112, note that the PulseCount instruction for P_SW uses
configuration option 2 (Switch Closure), while P_LL must use option 0 (Pulse
Input).
CRBASIC EXAMPLE 18. CRBASIC EXAMPLE. Two Rain Gages on a CR200(X)
'Rain(1) is wired to P_SW and Ground
'Rain(2) is wired to P_LL and Ground with a
'100,000 ohm resistor connecting P_LL to Battery+
Public Rain(2)
Units Rain()=mm
DataTable(Hourly,True,-1)
DataInterval(0,60,Min)
Totalize(2,Rain(),False)
EndTable
BeginProg
Scan(10,Sec)
PulseCount(Rain(1),P_SW,2,0,0.254,0)
PulseCount(Rain(2),P_LL,0,0,0.254,0)
CallTable(Hourly)
NextScan
EndProg
11.4 SDI-12 Sensor Support
11.4.1 SDI-12 Command Basics
Commands have three components:
Sensor address (a) – a single character, and is the first character of the
command. Sensors are usually assigned a default address of zero by the
manufacturer. Wildcard address (?) is used in Address Query command.
Some manufacturers may allow it to be used in other commands.
Command body (e.g., M1) – an upper case letter (the “command”) followed
by alphanumeric qualifiers.
Command termination (!) – an exclamation mark.
An active sensor responds to each command. Responses have several standard
forms and terminate with (carriage return – line feed).
112