1 serial input, 2 serial output, 7 tcp modbus – Campbell Scientific NL115 Ethernet Interface and CompactFlash Module User Manual

Page 21: 8 dhcp, Serial input, Serial output, Tcp modbus, Dhcp

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NL115 Ethernet and CompactFlash

®

Module

7.1.6.1 Serial Input

The

TCPOpen() instruction must be used first to open up a TCP socket. An

example of this instruction is shown below. The first parameter in

TCPOpen()

is the IP address to open a socket to. “” means to listen on this port rather than

connect. The second parameter is the port number to be used. The third

parameter is buffer size. For a

SerialIn() instruction that will use this

connection, it gives a buffer size. The

TCPOpen() instruction returns the

socket number of the open connection or ‘0’ if it cannot open a connection.

socket =

TCPOpen(“”,6784,100)

Once a socket has been opened with the

TCPOpen() instruction, serial data

may be received with a

SerialIn() Instruction. An example of this instruction

is shown below. The first parameter is the string variable into which the

incoming serial data will be stored. The second parameter is the socket

returned by the

TCPOpen() instruction. The third parameter is the timeout.

The fourth parameter is the termination character. The last parameter is the

maximum number of characters to expect per input. For more information on

this instruction, see the CRBasic Editor Help.

SerialIn(Received,socket,0,13,100)

7.1.6.2 Serial Output

The

TCPOpen() instruction must be used first to open up a TCP socket. An

example of this instruction is shown below. The first parameter in

TCPOpen()

is the IP address to open a socket to. The second parameter is the port number

to be used. The third parameter is buffer size. The

TCPOpen() instruction

returns the socket number of the open connection or ‘0’ if it cannot open a

connection.

socket =

TCPOpen(“192.168.7.85”,6784,100)

Once a socket has been opened with the

TCPOpen() instruction, serial data

may be sent out with

SerialOut(). An example of this instruction is shown

below. The first parameter is the socket returned by the

TCPOpen()

instruction. The second parameter is the variable to be sent out. The third

parameter is the wait string. The last parameter is the total number of times the

datalogger should attempt to send the variable. For more information on this

instruction, see the CRBasic Editor Help.

result =

SerialOut(socket,sent,"",0,100)

7.1.7 TCP ModBus

With an NL115 attached, the datalogger can be set up as a TCP ModBus

Master or Slave device. For information on configuring the datalogger as a

TCP ModBus Master or Slave, see the ModBus section of the datalogger

manual.

7.1.8 DHCP

The IP address of the datalogger may be obtained through DHCP, if a DHCP

server is available. The DHCP address will be automatically assigned if there

is a DHCP server available and no static IP address has been entered. The IP

address should be available a few minutes after the datalogger has been

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