CHAPTER 1_______________________________________________________ GENERAL INFORMATION
CHAPTER 1GENERAL INFORMATION
Safety
Throughout the manual important instructions regarding the safety
considerations are focused as follows.
WARNING
CAUTION
NOTE
Warning denotes a hazard. It calls attention to a procedure, practice,
condition or the like, which, if not correctly performed or adhered to,
could result in injury to or death of personnel.
Caution denotes a hazard. It calls attention to a procedure, practice,
condition or the like, which, if not correctly performed or adhered to,
could result in damage to or destruction of part or all of the product.
Note highlights important information. It calls attention to an essential
procedure, practice, condition or the like.
Vaisala hereby represents and warrants all Products manufactured by Vaisala and sold
hereunder to be free from defects in workmanship or material during a period of twelve (12)
months from the date of delivery save for products for which a special warranty is given. If any
Product proves however to be defective in workmanship or material within the period herein
provided Vaisala undertakes to the exclusion of any other remedy to repair or at its own option
replace the defective Product or part thereof free of charge and otherwise on the same
conditions as for the original Product or part without extension to original warranty time.
Defective parts replaced in accordance with this clause shall be placed at the disposal of
Vaisala.
Vaisala also warrants the quality of all repair and service works performed by its employees to
products sold by it. In case the repair or service works should appear inadequate or faulty and
should this cause malfunction or nonfunction of the product to which the service was
performed Vaisala shall at its free option either repair or have repaired or replace the product in
question. The working hours used by employees of Vaisala for such repair or replacement
shall be free of charge to the client. This service warranty shall be valid for a period of six (6)
months from the date the service measures were completed.
This warranty is however subject to following conditions:
a)A substantiated written claim as to any alleged defects shall have been received by
Vaisala within thirty (30) days after the defect or fault became known or occurred, and
b)the allegedly defective Product or part shall, should Vaisala so require, be sent to the
works of Vaisala or to such other place as Vaisala may indicate in writing, freight and
insurance prepaid and properly packed and labelled, unless Vaisala agrees to inspect and repair
the Product or replace it on site.
This warranty does not however apply when the defect has been caused through
a)normal wear and tear or accident;
b)misuse or other unsuitable or unauthorized use of the Product or negligence or error in
storing, maintaining or in handling the Product or any equipment thereof;
c)wrong installation or assembly or failure to service the Product or otherwise follow
Vaisala's service instructions including any repairs or installation or assembly or service made
by unauthorized personnel not approved by Vaisala or replacements with parts not
manufactured or supplied by Vaisala;
d)modifications or changes of the Product as well as any adding to it without Vaisala's
prior authorization;
e)other factors depending on the Customer or a third party.
Notwithstanding the aforesaid Vaisala's liability under this clause shall not apply to any defects
arising out of materials, designs or instructions provided by the Customer.
This warranty is expressly in lieu of and excludes all other conditions, warranties and
liabilities, express or implied, whether under law, statute or otherwise, including without
limitation ANY IMPLIED WARRANTIES OF MERCHANTABILITY OR OF FITNESS
FOR A PARTICULAR PURPOSE and all other obligations and liabilities of Vaisala or its
representatives with respect to any defect or deficiency applicable to or resulting directly or
indirectly from the Products supplied hereunder, which obligations and liabilities are hereby
expressly cancelled and waived. Vaisala's liability shall under no circumstances exceed the
invoice price of any Product for which a warranty claim is made, nor shall Vaisala in any
circumstances be liable for lost profits or other consequential loss whether direct or indirect or
for special damages.
The PTU200 transmitter combines three measurement parameters:
pressure, temperature and humidity. The applications of the PTU200
range from calibration laboratory environmental condition monitoring
to laser interferometer active wavelength compensation and GPS
meteorological measurements.
The PTU200 transmitters are available with one or two pressure
transducers. Three different kinds of sensor heads can be used with
PTU200: HMP45A-P, HMP45D and Pt100.
The PTU200 transmitters use a RS232 or RS485 (optional) serial
interface and they are available also with a local display.
In outdoor applications, it is recommended to use the PTU200MIK
mounting kit with the PTU200 transmitters. In addition, a mounting
tripod is available to support the PTU200MIK in temporary field
installations.
Pressure measurement
The PTU200 series transmitters use a BAROCAP® silicon capacitive
absolute sensor developed by Vaisala for barometric pressure
measurement applications. The measurement principle of the PTU200
series digital transmitters is based on an advanced RC oscillator and
three reference capacitors against which the capacitive pressure sensor
and the capacitive temperature compensation sensor are continuously
measured. The microprocessor of the transmitter performs
compensation for pressure linearity and temperature dependence.
The HMP45A-P and HMP45D probes are designed for the
measurement of relative humidity and temperature. The humidity
measurement is based on a capacitive thin film polymer sensor,
HUMICAP180. The temperature measurement is based on resistive
platinum sensors. Both the humidity and the temperature sensors are
located at the tip of the probe and protected by a membrane filter.
The HMP45A-P probe has the HUMICAP180 polymer sensor and
the Pt 1000 resistive platinum sensor for RH and T measurements,
respectively. The 20 metres cable of the HMP45A-P is connected to a
board with a plug and thus the user can cut the cable to suitable length
and reconnect it easily. The HMP45A-P and the HMP45D have a
similar humidity output, but the temperature output is active in the
HMP45A-P (voltage output 0-1V) and passive in the HMP45D
(resistive output Pt 100). The HMP45D comes with a 3.5-meter
connection cable. The cable is soldered directly to the board inside the
transmitter.
When the humidity measurement is not required, the PTU200 can be
supplied with a small, high stability wire-type Pt100 temperature
sensor head.
CHAPTER 3___________________________________________________________ GETTING STARTED
CHAPTER 3GETTING STARTED
Mounting
Choose a place, which represents the environment to be measured, and
is as clean as possible. Air should circulate freely around the probe; it
ensures that the sensor head and the ambient air are at the same
temperature.
NOTE
NOTE
For outdoor installation of the PTU200 transmitter, it is
recommended to use a PTU200MIK mounting kit. For further
information, please contact Vaisala or Vaisala distributor.
Please take into a consideration that the pressure fitting supplied with
the transmitter is not a static pressure head and that the transmitter
cannot be used successfully as such in turbulent or high speed static
wind conditions.
The barometric pressure measurement accuracy quoted for the
PTU200 series digital transmitters does not include any wind or air
conditioning system measurement errors.
Electrical connections
PTU200 series transmitters have as a standard a RS 232C and as an
option a RS485/422 serial interface. Connect the RS 232C serial
interface and a power supply according to the following pin
assignment.
ABLE 3-1Pin assignment for RS 232C/TTL serial output
PINSIGNAL
1TX with diode
2TX/TXD/TXD inverted
3RX/RXD/RXD inverted
4external power on/off control
5ground for the RS 232C
6
7ground for supply voltage
8
9supply voltage (10...30 VDC)
TABL E 3-2Pin assignment for optional RS 232C/485/422
PINSIGNAL
1TX with diode
2TX/TXD/TXD inverted
3RX/RXD/RXD inverted
4external power on/off control
5ground for the RS 232C
6RS 485/422 LO
7ground for supply voltage and TTL level serial interface
8RS 485/422 HI
9supply voltage (10...30 VDC)
The factory settings of the PTU200 series transmitters are the
following:
TABL E 3-3Serial interface factory settings
Baud rate9600
Parityeven
Data bits7
Stop bits1
Duplexfull duplex
After having made the electrical connections, switch the power on,
and the transmitter responds indicating its type and the software
version.
PTU200 / 1.01
>
The transmitter is now ready to respond to any command available.
CHAPTER 3___________________________________________________________ GETTING STARTED
1
At power-up, the display will first show the transmitter type and the
software version. Then it switches to display the reading as defined
with the DFORM command (page 9).
Set the desired sending form according to software settings (described
starting from page 12) and select the sending mode for the transmitter
(see page 11).
Should there be any problems please check the jumper settings in
connector X15 and the settings in dip switch S1 inside the transmitter.
The settings should be as indicated in the figure below.
RX/RXD
RXD
TX
ON
S
TXD
TXD
X15
FIGURE 3-2Basic RS 232C jumper and dip switch S1 settings
Connecting the probe
As the cable of HMP45A-P is connected via screw terminals the user
can shorten the cable to desired length and reconnect it easily. The
cable wires are connected as shown in FIGURE 3-3.
NOTE
It is not recommend to unsold and then re-sold the wires of HMP45D
and PT100 sensor head.
The optional LCD display has an on/off selectable backlight for better
readability at any light conditions. The two rows of the display can be
defined to indicate different kind of information. The keypad of the
display cover can be used to inspect and change the parameters
available.
The format of the display is defined by using the serial command
DFORM (see page 15). There are two rows containing 16 characters
each; the user can define a maximum of 32 characters to be displayed,
16 characters on each row. The following fields in the display format
can be used:
pressure quantities (pressure, average, difference)
three-hour pressure trend and pressure tendency code
temperature quantity and relative humidity
units
error status and stability indicator
number and text fields
The following basic rules apply to the use of the keypad:
1.Use ENT key to acknowledge a new selection.
2.Use CL key to activate a parameter or unit to be changed or to
revert to the original display.
3.Use arrow keys to make a selection between functional
alternatives.
Only the display contrast can be adjusted if the KEYLOCK is ON.
The transmitter displays NO MODIFICATIONS ALLOWED message
for a few seconds before reverting to the original display. It is also
possible to inspect the settings of the transmitter although the
KEYLOCK has been turned ON.
1. Press ENT and the text UNIT starts blinking. Acknowledge it with
the ENT key (enter).
2. Press CL and the pressure unit in use starts blinking. Use arrow
keys to choose a desired unit and acknowledge it with enter.
3. The temperature unit in use starts blinking. Use arrow keys to
choose a desired unit and acknowledge it with enter. The
transmitter now returns to the original display.
Example of changing serial settings:
1. Press ENT and the text UNIT starts blinking. Choose SER by using
the arrow keys and acknowledge with enter.
2. Press CL and BAUD starts blinking. After pressing ENT, all the
available baud rates will be displayed. Use arrow keys to choose a
desired value and acknowledge it with enter. PARI starts blinking.
Press CL to exit or continue to change other serial parameters in
same way as the baud rate.
NOTE
Note that modifications made using the keyboard will affect the serial
interface settings, too.
FIGURE 4-1Available functions and selections of the local display
Select the desired sending mode for the transmitter. This is done with
a command SMODE.
SMODE Selecting the sending mode
SMODE x <cr>
where:
x = STOP, RUN, SEND or POLL
The SMODE command is used to set or inspect the sending mode of
the transmitter. The PTU200 series transmitters have four sending
modes: STOP, RUN, SEND and POLL.
In STOP mode, after power-up the transmitter outputs its type and
software version and then waits for further commands.
In RUN mode, continuous outputting starts automatically from powerup.
In SEND mode, a single message is automatically output after powerup.
POLL mode allows the communication with multiple transmitters or
other digital instruments connected to one serial bus. The transmitter
does not echo in POLL mode.
Examples:
>smode <cr>
Serial mode: STOP
>smode run <cr>
Serial mode: RUN
>smode send <cr>
Serial mode: SEND
>smode poll <cr>
Serial mode: POLL
>smode stop <cr>
Serial mode: STOP
>reset<cr>
NOTE
Remember to give the RESET command to initialize the new sending
mode.
Always give the RESET command after the SERI command to
activate the new serial bus settings.
ECHO Setting the serial bus echo on/off
ECHO x <cr>
where:
x=ONorOFF
The ECHO command can be used to set or inspect the echoing
condition of the transmitter. In OFF mode the transmitter does neither
output the '>' prompt character nor echo the given commands.
The FORM command can be used to set or inspect the output format
of the transmitter. The maximum length of FORM is 80 characters.
The user can define the following fields into the output format:
amount of decimals give number of decimals before a
quantity. Giving 4.2 before the
pressure quantity outputs a reading
with the following form: 1013.12
temperature quantity of PT100
and HMP45D sensor heads *)T
temperature quantity
of HMP45A-P *)TH
relative humidityRH
unitsU, UU, UUU, UUUU, UUUUU
serial number of the transmitterSN
error statusERR (three characters)
stability indicatorOK (uses three characters)
checksumsCS2, CS4
CSX
number fieldsn.m where: n = 0 - 9, m = 0 - 9
text fieldswithin “ “ characters
CR\ r or #r
LF\ n or #n
TAB\ t or #t
nnn ASCII code \ nnn or # nnn (cannot be 000)
*) The PTU200 transmitter cannot output + sign for pressure trend or
temperature reading; a space is output instead.
Use ESC-key to abort without changing the settings.
EFORM Defining the error output format
EFORM <cr>
The EFORM command can be used to define a user specific error
output format for the serial line. In case of an error, the transmitter
outputs the defined format instead of *****.
The DFORM command is used to define the format for the optional
LCD display. There are two rows containing 16 characters each. The
user can define the following fields into the display format:
pressure quantitiesP1, P2, P (average), PD
(difference)
pressure trend *)TRE (three-hour trend)
pressure tendencyA (three-hour tendency)
temperature quantity of PT100
and HMP45D sensor heads *)T
temperature quantity
of HMP45TH
relative humidityRH
unitsU, UU, UUU, UUUU, UUUUU
serial number of the transmitterSN
error statusERR (three characters)
stability indicatorOK (uses three characters)
number fieldsn.m where: n = 0 - 9, m = 0- 9
text fieldswithin “ “ characters
*) The PTU200 transmitter cannot output + sign for pressure trend or
temperature reading; a space is output instead.
Any previous DFORM definition may be removed and the original
factory setting restored with the following command:
>dform * <cr>
>
Example of setting the display format to show pressure, stability
indicator, pressure trend and pressure tendency:
>dform <cr>
4.2P""UUUUU OK \r \n
?""4.2P""UUUOK"trend " 2.1 TRE""UUU""A
<cr>
>
The PTU200 transmitter will show * instead of numeric values for
pressure trend and pressure tendency for three hours from power-up.
In case of error, the relevant error message will automatically appear
on the display. In this case, any other information defined using the
DFORM command will be replaced with an error message.