Vaisala HMP228 User Manual
Page 21
HMP228
M210282en-A
Operating Manual
15
makes it impossible to change the transmitter settings by mistake. The jumper
should be removed only for changing the settings and for calibration.
Change of settings
disabled
24V
Sensor connections
Current loop or
RS485 module
Ch1 Ch2
+ -
nc
Tx
GND
Rx
-
- +
+
X15
Figure 3.1.1
Location of the security lock jumper
When the security lock jumper is connected, some commands cannot be used,
see Chapter 4.
If you wish to take into use variables that are not included in the configuration
of your transmitter, contact Vaisala for more information.
3.1.2
Commands and security lock jumper
In order to prevent any tampering with the transmitter settings, the transmitters
cannot be calibrated, the analogue outputs set or the analogue output
quantities selected or scaled unless the security lock jumper has been
disconnected. The commands involved are:
•
serial commands: CRH, CT, FCRH, ACAL; AMODE, ASEL, ASCL
•
all LED commands
•
display/keypad commands:
Cali
ð
RH T
Analog outputs
Mode
ð
Analog outputs
ð
Mode
Scale
In the following, the description of these functions is preceded with a
reminder of the security lock jumper:
Disconnect the security lock jumper!