Delta OHM HD2001 Manual De Instrucciones página 6

1. TEMPerature CENtigrade or FAHRenheit: Selection of the unit of measurement
for the temperature between Centigrade or Fahrenheit.
2. BAUD RATE: Selection of the data transmission speed for data communica-
tion using the RS232C or RS485 serial port. Various values are available: 300,
1200, 2400, 4800 and 9600. We recommend using the maximum speed of 9600
baud.
3. PRiNT AUTO: 1 = YES, 0 = NO. Enables (= 1) or disables (= 0) the continuous
data transmission on the serial port (continuous printing) according to a fre-
quency equal to the interval set in the item INTV SEC. Date, time, temperature,
relative humidity, absolute humidity, mixing ratio, dew point, barometric pres-
sure, wind speed (in m/s or in ft/min) are printed. The units of measurement are
the same as those used on the display.
4. INTerVal SEConds. Print interval in seconds.
5. YEAR: Menu item to set the year. The date is kept until the instrument is on.
If the instrument is turned off when not connected to a PC, the date must be
reset from the keyboard. If it is connected to a PC and a power failure occurs,
when reconnecting the power the PC automatically updates the instrument date
without needing to use the keyboard.
6. MONth: Current month.
7. DAY: Current day.
8. HOUR: Current hour.
9. ESC ZEROs SEConds, MINutes: Current minutes. The seconds can be reset
by pressing ESC. In order to set the hour precisely, simply set it one minute in
advance and when the new minute strikes, press ESC. For example, if it is 11:
20.10 and you wish to correct the time, set it to HOUR=11, MIN=21 and when
the new minute strikes (21), press ESC: thus the time is synchronized to the
second at 11:21.00.
10. NUMber INSTument ADDRess: Sets the identification (ID) of the instrument to be
able to use it within a network. The numbers from 0 (first instrument) to 255 are
available. For the details see the paragraph dealing with serial communication.
11. SET ALaRM 1 = YES, 0 = NO: Enables (=1) or disables (=0) the open collector
low-activated alarm output. The settings submenu can be entered using the
upward arrow (UP). For the details see the paragraph on alarm programming.
12. ENaBLe CALibration: Enables the calibration of the relative humidity sensor.
For the details see the paragraph on calibration.
Installation and connections
The instrument is set up to work indoors. The pressure and humidity sensors are set
downwards so that the accumulation of dust and dirt is reduced to the minimum.
Four holes fix the container: the position of the holes is outlined in the figure.
Model HD2001.2
The HD2001.2 model is fitted with an omnidirectional hot-wire probe: the sensor set
on the top of the probe is very delicate and must be protected with the special frame
provided with the instrument. During transportation, the sensor is closed into a cyl-
inder screwed on the end part of the probe: during installation, unscrew this cylinder
and screw the protection frame in its place.
In order to measure the wind speed accurately, the instrument must be set at a cer-
tain distance from the wall using the HD2001.2.30 pole, as indicated in fig. 3.
Serial communication and instruments' network
The instrument is fitted with RS232C and Multidrop RS485 serial ports for connec-
tion to a PC. Thanks to the RS485 protocol it is possible to connect more than one
instrument to form a network managed by the DeltaMet8 software provided.
The protocol is selected by using dip-switch no. 1 set on the display board.
When only one instrument is used, set at a maximum distance of 15 m from the PC,
use the RS232C serial connection, as this port, unlike RS485, is present on all PCs.
To cover longer distances (until 1200 m) or to create a network of instruments, the
RS485 port must be used with a special RS232/RS485 converter.
A network is formed by a maximum of 256 devices tandem-connected through a
shielded twisted pair cable. The first element of the network connected to the PC
may use the RS232C protocol and can be an interface between the PC and the rest
of the network: so using an RS232C/RS485 converter can be avoided (only if the
first instrument is less than 15 m away from the PC).
In order that communication along the network work correctly, each instrument
needs to be identified by an ID number differing from all the others. On the first
start up, after commuting the protocol selection dip-switch, the ID of the instrument
is automatically set to "0" if the RS232C protocol is selected, and set to "1" if the
RS485 protocol is selected: using the menu item "NUMber INSTument ADDRess"
these IDs can be changed and memorized in order to set up new components on
the network. To maximally speed up the data transmission, we recommend using the
highest baud rate available of 9600 baud: you should only reduce this value when
communication problems occur.
Fig.2 Hot-wire probe for HD2001.2.
HD2001
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