Vaisala HMP228 User Manual

Page 20

HMP228
Operating Manual

M210282en-A

COMMISSIONING

When the HMP228 transmitter leaves the factory, its measurement ranges and
output signals have already been scaled according to the order form completed
by the customer. The unit is calibrated at the factory and ready to operate
when the power is turned on. If you take into use active current, voltage or
serial bus outputs, make these connections first; appendix 9 describes them in
detail.

NOTE

Make sure that the power is not turned on until cables
have been connected to screw terminals!

In transmitters with display, the software version appears for a few seconds
when the power is turned on. After this, measurement results appear
automatically. Should an error message appear on the display, consult
Appendix 6.

If your transmitter has a blank cover and the LED indicator inside the housing
lights up, consult Appendix 6 for further information.

Appendix 7 contains information on how to determine the ranges for alarm
outputs and alarm controls when an alarm output unit is used, and Appendix 8
describes the use of connectors.

3.1

Changing the parameters

If necessary, the user can subsequently change the measurement units between
metric and non-metric and select and scale the output signals with software
functions. This is done through commands, either utilizing the menus on the
local display or giving commands through the serial interface (see
Appendices). Most often the commands are used to change the settings of the
two analogue channels.

A limited range of commands can be given with the three press switches (up,
down, enter) inside the transmitter housing. There are four LEDs to indicate
the commands given with the up and down switches. All HMP228 units
incorporate these switches and LED indicators. LED commands can be used to
calibrate the transmitters (both humidity and temperature) or to calibrate the
analogue outputs.

If you need to change some functions, read the following chapters carefully.

3.1.1

Security lock jumper

Before the settings can be changed, the user must first remove the security
lock jumper in connector X15 (see Figure 3.1.1). The security lock jumper