Campbell Scientific CR23X Micrologger - Manual (Page 295)

H-1
APPENDIX H
CALL ANOTHER DATALOGGER VIA PHONE OR RF
H.1 INTRODUCTION
Instructions 97, Initiate Telecommunications,
and 63, Extended Parameters can be used to
call another datalogger and collect data in input
locations. This function can only be
accomplished via phone or radio modems.
H.2 PROGRAMMING
Instruction 97 initiates the call and Instruction 63
specifies the dialing path and special options.
More than one Instruction 63 may be required.
The calling datalogger’s program requires
Instructions 97 and 63 for each datalogger it
calls. Only one datalogger can be called with
each set of instructions.
When the calling datalogger executes
Instruction 97, it establishes communication and
then toggles a flag in the remote datalogger.
After a specified delay, the calling datalogger
monitors that same flag (in the remote
datalogger). When the calling datalogger
detects the flag is low, it collects the specified
input locations. The collected values are stored
in the calling datalogger’s input locations
beginning at the location after the “failure
location” (Parameter 7 of Instruction 97).
In the example below, the remote datalogger is
programmed to make measurements when its
flag 1 is high and then set flag 1 low. The
calling datalogger toggles flag 1 and then waits
until flag 1 is low to collect the data, insuring
that the input location values are transferred
after the desired measurements and processing
are complete.
Section H.2 covers programming requirements
for the calling CR23X. Section H.3 shows the
programming requirements for the remote
datalogger.
H.3 PROGRAMMING FOR THE
CALLING CR23X
Programming Example 2.1 uses a COM200
phone modem while Programming Example 2.2
uses a RF modem.
H.3.1 INSTRUCTION 97
Many of the parameters in Instruction 97 don’t
apply when being used to call another
datalogger. See Section 12 for more detailed
information on Instruction 97’s parameters.
PAR. DATA
NO. TYPE DESCRIPTION
01: 2 Modem/Baud Option
02: 2 Flag No. to Disable Instruction 97
03: 4 Seconds Call Time Limit
04: 4 Seconds Before Fast Retry
05: 2 Fast Retries
06: 4 Minutes Before Slow Retry
07: 4 Failures Loc :
08: 4 Datalogger ID
Parameter 1
This specifies the first modem type to call out
through and the appropriate baud rate. See
Table H.3-1 for valid options. An RF modem is
in the SDC state when the 9th dip switch is
closed.
TABLE H.3-1. Option Code for Modem Type
and Baud Rate
Baud Rate
Modem 300 1200 9600
RF, ME State 00 01 02
Phone (DC112/COM200) 20 21 22
Voice Data 40 41 42
RF, SDC State 50 51 52
Parameter 2
This specifies the flag lowered in the calling
datalogger to initiate the call to the other
datalogger. This should not be confused with
the flag that the calling datalogger sets in the
remote datalogger (specified in Instruction 63).
Parameter 3
This is the total length of time the calling
datalogger will try to collect input locations from
the remote datalogger. The timer begins when
a call is initiated and includes the dialing time.
This timer must be long enough for the remote
datalogger to detect that a flag has been set
(i.e., long enough to allow for the execution