Campbell Scientific CR23X Micrologger User Manual

Page 149

SECTION 9. INPUT/OUTPUT INSTRUCTIONS

9-15

NOTE: When the raw serial data option is
selected, the calibration values are for
conversion to millivolts only. Parameters 11
and 12 are ignored.

SCAN INTERVAL
Instruction 23 has its own scan interval
independent of the execution interval of the
program table in which it resides. The
resolution of the clock timing the execution
interval is 407 nanoseconds. This scan interval,
entered in Parameter 5 (in milliseconds), is the
time between each scan of the specified
channels (i.e., if 4 channels are specified in
Parameter 1, and the scan interval is 5 ms, then
the 4 measurements will be repeated every 5
ms). The minimum time that is allowed per
measurement is 0.6666 ms. The maximum
time that is allowed per measurement is 25 ms.
If the scan interval entered does not allow this
much time per measurement (e.g., if with 4
reps, an interval less than 2.666 ms is entered),
an error code, E 61, will be displayed when the
program is compiled. When sending data to the
serial port, the rate at which the data can be
transferred may limit the scan interval (e.g., at
9600 baud the minimum time per measurement
is 2.2 ms).

Burst/Telecommunications Considerations

If a Burst measurement sequence is in
progress, raising the datalogger's ring line will
abort the Burst sequence. Peripherals which
raise the ring line are modems (i.e., RF,
Telephone, Short Haul, MD9, SC32A).

If the Burst Measurement Instruction is
encountered while telecommunications is in
progress, the destination of the data determines
whether or not the instruction is executed:

Burst data sent to input locations

If a CR23X already in Telecommunications
mode executes a Burst instruction specifying
that Burst data be sent to input locations, all
telecommunication activity will be suspended.
After the Burst trigger condition is met and all
Burst measurements made,
telecommunications activity can resume.

Burst data sent to CS I/O or Computer
RS-232 Port

If the Burst instruction specifies that Burst data
be sent to the serial port (i.e., Storage Module),

CR23X program execution will pause until the
Telecommunication mode is exited. During this
pause telecommunications (i.e., view input
locations in the Monitor Mode, etc.) can
continue. No Burst measurements are made
while in telecommunications and no Burst data is
sent to the serial port. After telecommunications
has ended, datalogger program execution will
resume as if the Burst instruction were just
executed.

NOTE: Instruction 23 can be aborted by
pressing any key on the CR23X Keyboard.

PARAM.

DATA

NUMBER

TYPE

DESCRIPTION

01:

Input channels per
scan (reps)

02:

Range code

03:

Single-ended or
differential channel for
first analog
measurements

04:

Option, 4 digit code
ABCD
A

Trigger
0 - Trigger on 1st
analog channel
1 - Digital trigger
on Control Port #1
2 Same as 0, but
set Digital Control
Port #1 high when
trigger is met, low
when done
measuring

Trigger option
0 - Trigger
immediately
1 - Trigger if
above limit (high)
2 - Trigger if below
limit (low)
3 - Trigger on
rising edge
4 - Trigger on
falling edge

Destination
0 - Input Storage
1 - CS I/O port
9600 baud
2 - CS I/O port
76,800 baud