12. Troubleshooting
12. TROUBLESHOOTING
The data logger ALMEMO 2890-9 can be configured and programmed in many
different ways. It allows for a connection of many different sensors, additional
measuring instruments, alarm signalisers and peripheral devices. Due to the
large variety of options it is possible that, under certain conditions, it does not
perform as the user would expect. In most cases this will not be related to a
defective device but to operating errors such as wrong settings or an inadmis-
sible wiring. The following tests should be performed to correct or to correctly
identify the error.
Error:
No display at all or faulty display, no key response
Remedy:
Check power supply, recharge battery, switch off and on again, reini-
tialise, if required (see point 7.5Fehler: Referenz nicht gefunden)
Error:
Incorrect measured values
Remedy:
Thoroughly check the entire programming of the channel, particularly
base and zero point (menu ´Sensor Programming´ and ´Special
Functions´)
Error:
Varying meas. values or blockage during operation
Remedy
:
Check cabling for inadmissible electrical connection,
disconnect all suspicious sensors,
connect hand-held sensors and operate them in air or connect dum-
mies (short circuit AB at thermocouples, 100
W
at Pt100 sensors)
and check,
then reconnect sensors successively and check.
If an error occurs with one sensor, check the wiring, isolate the sen
sor if necessary, prevent influences from disturbances by shielding or
twisting.
Error:
Data transmission via interface does not function
Remedy:
Check interface module, connections and setting:
Are both devices set to the same baud rate and transmission mode
(s. 11.5.3)?
Is the correct COM interface addressed at the computer?
Is a printer in ONLINE mode?
Are the handshake lines DTR and DSR active?
A small interface tester with LEDs is very useful for checking the data flow
and the handshake lines (during standby mode the data lines TXD and RXD
are on a negative potential of approximately -9V and the LEDs are illumi-
nated green. The handshake lines DSR, DTR, RTS and CTS have a positive
voltage of approxi9V and the LEDs are illuminated red. During the
data transmission the data LEDs must flash red).
Test the data transmission by using a terminal (AMR-Control, WIN-
Control, WINDOWS Terminal):
74 ALMEMO
®
2890-9