Campbell Scientific NL120 Ethernet Module - Manual (Page 13)

NL120 Ethernet Module
6.1.2 Datalogger-to-Datalogger Communication
Communication between dataloggers is possible over TCP/IP. In order to do
this, a socket must be opened between the two dataloggers. This is done using
the TCPOpen() instruction. The socket opened by this instruction is then used
by the instructions performing datalogger-to-datalogger communication.
The example program below gets the battery voltage from a remote datalogger
and sends its panel temperature to the remote datalogger. The remote
datalogger is at IP address 192.168.7.125 and port 6785 is used for
communication between the dataloggers. The remote datalogger must have its
battery voltage stored in a public variable, BattVolt. It must also have a Public
variable declared, PTemp_Base. This will be used to store the panel
temperature of the base datalogger.
PROGRAM
'CR1000
'DL-to-Dl_Comms_1.cr1
'Send this program to CR1000 #1
'Remote CR1000 #2 has PBA = 2, IP addr = 192.168.7.125, and port 6785
Public BattVolt,, BattVolt_Remote
Public PTemp
Public Result1, Result2
Dim Socket as LONG
DataTable (Test,1,-1)
DataInterval (0,12,Sec,10)
Minimum (1,BattVolt,FP2,0,False)
EndTable
BeginProg
Scan(2,Sec,0,0)
Socket = TCPOpen(“192.168.7.125”,6785,0)
BatteryVoltage(BattVolt)
PanelTemp(PTemp,250)
GetVariables (Result1,Socket,-1,2,0000,50,"Public","BattVolt",BattVolt_Remote,1)
SendVariables (Result2,Socket,-1,2,0000,50,"Public","PTemp",PTemp_Base,1)
CallTable(Test)
NextScan
EndProg
6.2 HTTP Web Server
Typing the datalogger’s IP address into a web browser will bring up its home
page as shown in FIGURE 6-1. This default home page provides links to the
current record in all tables, including data tables, the Status table and the Public
table. Clicking on a Newest Record link will bring up the latest record for that
table. It will be automatically refreshed every 10 seconds. Links are also
provided to the last 24 records in each data table. Clicking on a Last 24
Records link will bring up the last 24 records for that table. The Last 24
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