Detailed instructions for use are in the User's Guide.
[. . . ] HMI38 HUMIDITY DATA PROCESSOR AND HMP35/36/37E PROBES Operating Manual
U063en-2. 1 June 1998 © Vaisala 1998
© Vaisala Oyj 1998 No part of this document may be reproduced in any form or by any means, electronic or mechanical (including photocopying), nor may its contents be communicated to a third party without a prior written notice of the copyright holder. The instruction manuals may be changed without prior notice.
Yleisjäljennös 06/1998
U063en-2. 1
HMI38 Operating Manual
Contents
1. PRODUCT DESCRIPTION. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 TO BE NOTED WHEN MEASURING HUMIDITY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . [. . . ] Setting the output interval for the RUN state INTV xxx yyy <cr> xxx = yyy = output interval (0. . . 255) unit (s, min or h)
Sets the output interval for RUN mode and command R. If the interval is set to zero (s, min or h), the output interval will be determined by the frequency of measurements only. Example: Changing output interval to 10 minutes
>INTV 10 min <cr> Output intrv. : 10 min
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5. 2. 2. 5.
Serial bus settings SERI b p d s x <cr> b p d s x = = = = = bauds (300, 600, 1200, 2400, 4800, 9600) parity (n = none, e = even, o = odd) data bits (7 or 8) stop bits (1 or 2) duplex (H = half, F = full)
Examples: Giving new settings
>SERI O H <cr> 4800 O 7 1 HDX >SERI 600 N 8 2 F <cr> 600 N 8 2 FDX
changing parity and duplex only changing all parameters
NOTE
New settings are effective only after switching the instrument off/on or after the serial command RESET has been given. If half-duplex setting is used with RS 485 bus, it will automatically turn the echo off. Selecting the output units UNIT x <cr> x = m(etric units) n(on-metric units) metric %RH °C °C g/m3 g/kg °C non-metric %RH °F °F gr/ft3 gr/lb °F
RH T Td a x Tw
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5. 2. 2. 7.
Setting the address ADDR aa <cr> aa = address (0. . . 99)
Example: The HMI38 is given address 99
>ADDR <cr> Address : 0?99 <cr>
5. 2. 2. 8.
Resetting the HMI38 RESET <cr>
5. 2. 3. Operating the HMI38 via the serial bus Setting the serial interface mode SMODE xxxx<cr> xxxx = STOP, RUN or POLL measurements output only by command, all commands can be used outputting automatically, only command S can be used measurements output only with command SEND.
In STOP mode: In RUN mode: In POLL mode:
When in POLL mode, the output mode is changed as follows: OPEN aa <cr>
SMODE xxxx<cr> aa = xxxx = address of the transmitter STOP, RUN or POLL
The OPEN command sets the bus temporarily in STOP mode so that the SMODE command can be given. Example:
>SMODE STOP <cr> Serial mode : STOP
setting STOP mode
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5. 2. 3. 1.
OPEN & CLOSE OPEN nn <cr> nn = address of the transmitter (0. . . 99) CLOSE <cr> In STOP mode: In POLL mode: OPEN has no effect, CLOSE sets the serial bus temporarily to the POLL mode OPEN sets the serial bus temporarily to STOP mode; CLOSE sets the bus back to POLL mode
The temporary mode changes are not stored in the memory of the transmitter; after reset the bus is in its original mode. When more than one instrument is connected to the same serial bus, the POLL mode enables communication with an individual instrument. Example: Transmitter 2 is temperature calibrated (currently in POLL mode)
>OPEN 2 <cr>
this line is not visible on the screen
HMI 2 line opened for operator commands >CT <cr> . . . >CLOSE <cr> line closed
calibration procedure
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6.
DATA LOGGING
The HMI38 has two data logging modes: the CONTINUOUS mode, i. e. automatic logging which can store up to 254 readings from both probes and the CATCH mode, i. e. manual logging with which the user can store up to 127 readings from both probes. The user can choose the logging interval and starting time of the logging when using the CONTINUOUS mode, and in the CATCH mode he can store readings at any given moment by pushing the button ENT. The HMI38 stores the measured relative humidity and temperature values and when the stored data is transferred to a computer or peripheral through the serial bus, it calculates the other four quantities dewpoint temperature, mixing ratio, absolute humidity and wet bulb temperature from them.
NOTE
The CATCH mode is available only in units that have the software version 2. 01 or more. You can easily check the version by reading the sticker on back of the device (SV2 indicates software version 2. 01 or more). In outputting the values for mixing ratio and wet bulb temperature, the currently valid pressure setting is used.
NOTE 1
To save battery, the analogue outputs cannot be used when data logging is on.
NOTE 2
When the HMI38 is powered from the battery and the logging memory becomes full, the instrument automatically turns itself off.
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6. 1.
Logging using display/keypad commands 6. 1. 1. Start/stop data logging in the CONTINUOUS mode
NOTE
The HMI38 has no battery operated real-time clock. Give current date and time settings manually after power-on (see Chapter 5. 1. 6. 5); this way, correct time and date indications are stored with each reading. The LOGG menu is displayed:
·
Select Start and in the START menu, select Continuous:
·
The current delay (time before logging starts) and interval (time between sequential data storings) settings appear on the display with the current delay blinking:
·
Press ENT to acknowledge the current delay time setting. Enter the new time and press ENT, then choose the correct time unit (s, min, h) with the arrow keys and press ENT. [. . . ] The potentiometer used for adjusting the transmitter varies depending on the transmitter type and the humidity level in which you perform the calibration (see the transmitter manual). HMW20/30 UB/YB (wall mount transmitters):
·
use the "DRY" or one-point calibration trimmer potentiometer (see the sticker inside the transmitter cover)
HMD20/30 UB/YB (duct mount transmitters):
· ·
if the reference humidity is below 65 %RH use the "DRY" trimmer potentiometer if the reference humidity is above 65 %RH use the "WET" trimmer potentiometer
HMP130Y series:
· ·
if the reference humidity is below 65 %RH use the trimmer potentiometer R5 (offset) if the reference humidity is above 65 %RH use the trimmer potentiometer R18
Wait until the readings stabilize and adjust the transmitter reading to correspond to the reference reading or adjust the difference reading to zero. Turn the power of the HMI38 off and on again to return to normal operation.
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9.
9. 1.
MAINTENANCE
Reference measurements Reference measurements help to verify whether the instrument readings are within specifications. This way the user can check if the probe or the indicator needs calibration or service. [. . . ]