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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. For more information on this instruction, see the CRBasic Editor help.
result = SerialOut(socket,sent,"",0,100)
7.1.7 TCP ModBus
With an NL116 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
powered up with the NL116 attached and Ethernet cable plugged in. The IP
address can be found with the DevConfig Settings tab under TCP/IP Info. It
can also be found using a CR1000KD attached to the datalogger. Go to
Configure, Settings | Settings (general), scroll down to IPInfo and press the
right arrow.
An IP address obtained through DHCP is not static but is leased for a period of
time set by the network administrator. The address may change, if the
datalogger is powered down.
7.1.9 DNS
The datalogger provides a DNS client that can query a DNS server to resolve a
fully qualified domain name. When a DNS server is available, domain names
can be used in place of the IP address in the datalogger instructions.
7.2
File Formats
This section covers the different types of files stored on the CF card.
7.2.1 Data Files
The datalogger stores data on the CF card in TOB3 format. TOB3 is a binary
format that incorporates features to improve reliability of the CF cards. TOB3
allows the accurate determination of each record's time without the space
required for individual timestamps.
TOB3 format is different than the data file formats created when data is
collected via a communication link. Data files read directly from the CF card
generally need to be converted into another format to be used.
When TOB3 files are converted into another format, the number of records
may be slightly greater or fewer than the number requested in the data-table
declaration. There is always some additional memory allocated. When the file
is converted, this will result in additional records if no lapses occurred. If more
lapses occurred than were anticipated, there may be fewer records in the file
than were allocated.
NL116 Ethernet and CompactFlash
®
Module
19
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