Introduction; Example Phone Callback Program Based On A Condition; D.1 Introduction; D.2 Example Phone Callback Program Based On A Condition - Campbell CR510 Operator's Manual

APPENDIX D. DATALOGGER INITIATED COMMUNICATIONS
Datalogger initiated communications, commonly referred to as "callback," is when the datalogger initiates
a call back to a computer. A CR510 uses Instruction 97 to initiate a call. For complete information on
Instruction 97 and its parameters, refer to section 12.

D.1 INTRODUCTION

In most applications, the datalogger initiates a
call to the computer to notify the user that a
specific condition has occurred. For example, a
station monitoring conditions at a dam could be
setup to call the computer to notify the user
when the water level gets above a specified
level. Another example would be a CR510
initiating a call to a PC when conditions in a
control environment are not within acceptable
ranges. Datalogger initiated calls can also be
triggered based on time (Instruction 92).
This appendix gives an example of a CR510
calling a computer via a COM200 Phone
Modem whenever the temperature exceeds 32
C. An example program, the necessary
computer files, and setup are included. This is
only an example, instruction parameters should
be changed to match your system.
D.2 EXAMPLE PHONE CALLBACK
PROGRAM BASED ON A CONDITION
The following program example measures a
HMP35C Temperature/RH sensor every 30
seconds and stores hourly data. Whenever the
temperature is above 32 C, the datalogger
initiates a call to a dedicated computer.
Instruction 97 uses the status of a Flag to
determine when to initiate the call. Any user
flags (1-8) may be used as Instruction 97's
Interrupt Flag. In this example when
temperature is within acceptable limits
(< 32 C), Flag 5 is set high, otherwise Flag 5 is
set low. If Flag 5 is low when Instruction 97
executed, the datalogger will attempt to call the
computer.
Once the computer answers the datalogger's
call, the datalogger sends a 3 digit ID#
(Parameter 8 of Instruction 97). This ID# is the
"name" of the site. Each site that calls a
computer needs to have a unique 3 digit ID#.
The computer's software will use this 3 digit ID#
to identify which datalogger is calling and what it
should do as a result of the call. Section D.3
covers the DOS software setups for this
example program. Section D.4 covers the
Windows software setup of this example
program.
When this CR510 tries to call, it will dial out the
phone number given in Instruction(s) 63. If the
datalogger is dialing 7 or less digits, the second
Instruction 63 in not needed. If the datalogger
needs to dial 8 digits, a second Instruction 63 is
still required to dial the 13. Do not forget to
put a 13 for the last parameter in the last
Instruction 63. This is the only way the CR510
knows when to stop sending characters and to
instruct the COM200 to make the call.
PROGRAM
*Table 1 Program
01: 30 Execution Interval (seconds)
1: Batt Voltage (P10)
1: 3 Loc [ BATT_VOLT ]
2: Temp (107) (P11)
1: 1 Reps
2: 1 SE Channel
3: 2 Excite all reps w/Exchan 2
4: 1 Loc [ AIR_TEMP ]
5: 1 Mult
6: 0 Offset
3: Do (P86)
1: 4 Set Port 1 High
4: Excitation with Delay (P22)
1: 1 Ex Channel
2: 0 Delay W/Ex (units = 0.01 sec)
3: 15 Delay After Ex (units = 0.01 sec)
4: 0 mV Excitation
5: Volts (SE) (P1)
1: 1 Reps
2: 25 ± 2500 mV 60 Hz Rejection
Range
3: 2 SE Channel
4: 2 Loc [ RH
5: .1 Mult
6: 0 Offset
]
D-1