wtw: Control a WTW instrument of series P3, P4, 340, 340i or 197i

Description Usage Arguments Value Note Author(s) See Also Examples

Description

Connect to a compatible WTW instrument using a serial (com) port through the control cable AK340/B and send commands and/or read values of pH, O2, etc.

Usage

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wtw_open(port = getOption("wtw_port"))

wtw_close(port = getOption("wtw_port"))

wtw_ready(port = getOption("wtw_port"))

wtw_sim()

wtw_cmd(code, port = getOption("wtw_port"))

wtw_echo(port = getOption("wtw_port"))

wtw_info(port = getOption("wtw_port"), timeout = 1000)

wtw_read(port = getOption("wtw_port"), timeout = 1000, O2 = FALSE)

wtw_record(
  file = NULL,
  interval = 10,
  Nmax = 10,
  port = getOption("wtw_port"),
  timeout = 1000,
  O2 = TRUE,
  init.data = NULL,
  graph = TRUE,
  title = "WTW record",
  ...
)

Arguments

port

A serial port as "com1", or the port number as 1.

code

Code to send to the WTW instrument, i.e., "K.1" -> "K.19" to simulate keystrokes (simple or double), and "D.0" -> "D.12" to read display items (see the WTW communication protocole manual).

timeout

Maximum time to wait in ms for the answer from the instrument.

O2

For instruments that support it, do we also read O2 values?

file

The file where to write the records. If NULL, a default name is computed which is 'WTW_<date>.txt' in the temporary directory. If it is NA, nothing is written in a file.

interval

Interval between two measurements, in second.

Nmax

Maximum number of readings to record.

init.data

A data frame with data to start with (append data to it).

graph

Do we update a graph each time new item is read?

title

The title of the graph.

...

Further graph arguments.

Value

wtw_open() returns TRUE in case of success, FALSE otherwise. wtw_ready() does the same if the instrument is ready or not.

wtw_close() returns the com port that was closed.

wtw_info reads the identifier of the WTW instrument and returns it (if it is one of the recognized devices).

wtw_echo() echo data send by the instrument to the console (mainly for debugging purpose). Use wtw_read() instead to read measurements.

wtw_sim() simulates data read from a fake instrument. You can define your own function, if you like.

wtw_record() records a series of measurement on a disk file, and possibly plot the data in real time. Note that this is the only function that does not require that you open (wtw_open()) before, and close (wtw_close()) the port before interacting with the instrument.

Note

A fake instrument for test and set up of control programs is available if you specify "com0" as serial port. Note that, for simulations, you can speed up globally data acquisition by defining option(econum_speed = X). If 'X' is higher that 1, it means everything is done faster (X = 10 means ten times faster). If 'X' is lower that 1, everything is acquired at a slower pace: X = 0.1 means ten times slower.

Do not forget to close the port after use!

Author(s)

Philippe Grosjean Philippe.Grosjean@umons.ac.be

See Also

iks_open(), gce8_open()

Examples

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# Use the fake WTW instrument on com0
oport <- options(wtw_port = "com0") # Change this to connect to a real instrument
wtw_open()
wtw_echo()	# Echo data send by run/enter from the instrument
wtw_read()  # Read data from the instrument
wtw_ready() # Check that instrument is ready
wtw_close()
wtw_ready()	# Not ready any more, because we closed the port

# Record 10 data with an interval of 1 sec and make a graph...
# but speed up things by ten times if we use a fake instrument
if (getOption("wtw_port") == "com0") options(econum_speed = 10)
# Record ten data points (and do not save to a file)
# Note that you don't have to open/close the port with this function!
wtw_record(file = NA, interval = 1, Nmax = 10)
# Restore default speed
options(econum_speed = NULL)
# Restore port
options(oport); rm(oport)
rm(wtw_dat)

EcoNum/econum documentation built on May 9, 2020, 3:57 a.m.