Vaisala HMP228 User Manual

Page 24

HMP228
Operating Manual

M210282en-A

3.3

Using LED commands

NOTE

If the transmitter has a display/keypad cover, the LED
commands cannot be used.

LED commands can be used to operate the transmitters in the field. These
commands can be used in humidity and temperature calibration and calibration
of the analogue outputs.

Open the housing and press any one of the three press switches. The LEDs
will light up for 2...3 seconds.

DOWN

ENT

24V

Sensor connections

Current loop or
RS485 module

Ch1 Ch2

+ -

GND

- +

LEDS

PRESS SWITCHES

Figure 3.3

Location of press switches and LEDs

Use the up and down switches (marked with arrows on the printed board) to
find the desired command code and acknowledge it with the ENT switch. The
command codes are (l = lit, ¡ = dark):

¡¡¡¡ (0)

return to normal state

¡¡¡l

(1)

relative humidity calibration

¡¡l¡

(2)

temperature calibration

¡¡ll

(3)

calibration of analogue outputs

l¡¡l

(9)

forced auto-calibration (one auto-calibration; the
security lock jumper must be connected)

3.4

Using display/keypad commands

3.4.1

Display mode

In the display mode the transmitters output measurements on the display; dif-
ferent quantities can be scrolled with the arrow keys. The first line is scrolled