Campbell Scientific CR510 Basic Datalogger - Manual (Page 113)

SECTION 9. INPUT/OUTPUT INSTRUCTIONS
9-9
*** 22 EXCITATION WITH DELAY ***
FUNCTION
This instruction is used in conjunction with
others for measuring a response to a timed
excitation using the switched analog outputs. It
sets the selected excitation output to a specific
value, waits for the specified time, then turns off
the excitation and waits an additional specified
time before continuing execution of the following
instruction. Analog power is turned off during
delay after excitation to drop power to 3 mA.
If the excitation channel is indexed, parameter 4
becomes an input location. The excitation
voltage must be loaded into the specified input
location before Instruction 22 is executed.
If the only requirement is the delay of program
execution, the excitation on time (parameter 2)
can be set to zero and the off time delay
(parameter 3) can be used.
PARAM. DATA
NUMBER TYPE DESCRIPTION
01: 2 Excitation channel
number
02: 4 Delay time in
hundredths of a second
that excitation is on
03: 4 Delay time in hundredths
of a second after
excitation is turned off
04: 4 Excitation voltage in
millivolts
or
input location, when the
excitation channel
(Param. 1) is indexed
Input locations altered: 0
Input locations read: 0 or 1
*** 24 CALIBRATION ***
FUNCTION
Put the CR510’s 19 calibration values into input
locations. If C (--) is keyed before entering the
input location, then the automatic calibrations
are simply displayed, not measured. Otherwise,
the calibration takes place only when Instruction
24 is executed; automatic calibration is disabled
See Section 13.7 for details abut the CR510’s
calibration process.
PARAM. DATA
NUMBER TYPE DESCRIPTION
01: 4 Input location number,
key C (--) for results of
automatic calibration
Input locations altered: 19
*** 25 PORT READ ***
FUNCTION
The status of C1 is read and placed in an input
location. The status is a base 2 representation
of the port converted to base 10. For example,
if port one is read and the port status is as
follows:
PORT C1
VALUE 1
STATUS 1
(0=low,
1=high)
Base 10 equivalent: 1 = 1
1 will be stored in the input location.
The mask is also base 2 representation; 1
indicates the port is to be read, 0 results in a 0
for the port regardless of the status of the port
(AND operation). For example, if 1 is entered,
port 1 is read.
NOTE: Voltages in excess of 5.5 volts
applied to a control port can cause the
CR510 to malfunction.
PARAM. DATA
NUM. TYPE DESCRIPTION
01: 4 MASK (0-255)
02: 4 INPUT LOCATION TO
STORE RESULT
Input locations altered: 1
*** 26 TIMER ***
FUNCTION
This instruction will reset a timer or store the
elapsed time registered by the timer in seconds in
an Input Storage location. Instruction 26 can be
used with Program Control Instructions to measure
the elapsed time between specific input conditions.
There is only one timer and it is common to all
tables (e.g., if the timer is reset in Table 1 and later