Vaisala DM500 User Manual
Page 78
User's Guide ______________________________________________________________________
76 __________________________________________________________________ M210205EN-D
The port connections are as follows:
pin 1: ch+ (+VDC supply voltage)
pin 2: ch- (-VDC supply voltage)
pin 3: test (for service use only)
pin 4: shield
When using 12V loop voltage, the resistance must be less than 90
ohms. An approximate can be calculated by following formula:
Rmax = (V
loop
- 10V)/20mA
You can scale the output to any output range. It is recommended to
have the scaling within the measuring range to get accurate
measurements.
1.
Connect the analog output signal cable connector to the
connector, see Figure 21 on page 73.
2.
Open
MENU
: press .
3.
Select ►
Interfaces
, press .
4.
Select ►
Analog outputs
, press .
5.
Select ►
Output 1
, press .
6.
Select
Quantity
, press
SET
, select the quantity for the analog
output and press
SELECT
.
7.
Select
Scale 4 mA
, press
SET
.
8.
Press
CLEAR
and give the lowest value (value represented by 4
mA current) by using numerical buttons. Press
OK
.
9.
Select
Scale ...20 mA
, press
SET
.
10.
Press
CLEAR
and give the highest value (value represented by
20 mA current) by using numerical buttons. Press
OK
.
11.
Select
ENABLED WHEN
, press
SELECT
. Now you can select the
measurement status that activates the analog outputs.
STOP: output is enabled when dewpoint measuring status is
STOP.
ERR: output is enabled when dewpoint measuring status is
ERR.
OK: output is enabled when dewpoint measuring status is OK