3. GENERAL OPERATION
Page 121
© 1998-2008 DH Instruments, a Fluke Company
PRINCIPLE
PG7000 uses atmospheric pressure values in its calculations of reference
pressure (see Section 7.2). The source of the value is determined by the AtmP
setting in the current SETUP file (see Section 3.10). One of the possible sources
is
COM2
, which allows an external barometer, connected to PG7000’s COM2
RS232 port to be read automatically to obtain the atmospheric pressure values
that are used. In order to communicate with an the external barometer PG7000’s
COM2 must be properly set up. This setup occurs by pressing
[SPECIAL]
and
selecting
<5remote>
,
<2COM2>
,
<2baro>
.
OPERATION
To set up PG7000’s COM2 port to communicate with an external barometer,
press
[SPECIAL]
and select
<5remote>
,
<2COM2>
,
<2baro>
. Select
<1RPMx>
if the external barometer is a
DHI
RPM. Select
<2user>
to set up
communications with a barometer other than a
DHI
RPM.
Setting Up for User Barometer Communications
For a remote barometer to be able to be used for automated atmospheric
pressure readings on PG7000 COM2, the following requirements apply to the remote
barometer’s communications:
•
Replies to a request to send string within 2 seconds.
•
Accepts <CR, LF> terminators.
•
Supplies <CR> or <CR, LF> terminators.
•
Request to send string must be printable alphanumeric (no control
modes or nulls).
After pressing
[SPECIAL]
and selecting
<5remote>
,
<2COM2>
,
<2baro>
,
<2user>
, the display is:
COM2 meas req string
The string value is entered on the second line. It may have up to 20 characters.
When
the string screen is opened, the cursor is on the first character.
Numerical values can be entered directly from the keypad. In addition, the
[
←
]
and
[
→
]
keys can be used to toggle through a list of available alpha numeric characters.
Holding the key steps through the characters. Character order going up (
[
→
])
is:
blank space, symbols, lower case letters, upper case letters, numbers
.
Press
[ENTER]
to select a character and move to the next character. When a
character is selected the cursor moves to the next character. To leave a character
blank, press
[ENTER]
with the field for that character blank. After the last character
has been entered, press
[ESCAPE]
. This causes a
<Save edits?>
screen
to appear. Select
<2yes>
to save the edited string and move to the next screen.
Select
<1no>
abandon the edits. Also, if
[ENTER]
is pressed on the 20
th
character,
the string is saved automatically and operation advances to the next screen.
The external barometer parameters including the communication string can
also be set by remote command, which is more convenient than front panel entry (see
Section 4.3.4.2, “UDD” command).
