5 – 4
Error Messages
5.1.8
Responsivity overflow
3#%3#/
E#*YX3"
When calibrating responsivity (see section 3.2.3.6), a small value for
measured power might result in the responsivity value greater than
the maximum, 999,999
μ
A
/
mW. If this occurs, the power measure-
ment is mistaken.
5.1.9
Trip-off from TEC
@//ABB@
A
This message indicates the laser diode driver has tripped o
ff
because
the TEC controller is o
ff
. This condition (armed by
ATOF
, see sec-
tion 3.2.3.9) shuts down the laser current source if the TEC turns o
ff
for any reason.
5.1.10
Trip-off from temperature
@//ABB@
EE
@//ABB@
E
@//ABB@
##%
Any of these messages indicate the laser diode driver has tripped o
ff
because of a temperature limit setting. Note that these conditions
can operate even when the TEC is o
ff
, as long as a valid temperature
sensor is connected.
5.2
TEC Messages
The following warning messages are related to the TEC Controller
section of the LDC500.
5.2.1
Autotune
*%%
B
If the thermal stage being controlled has an unusually long thermal
time constant (greater than around 50 seconds), the default autotun-
ing function may fail to converge because of the very slow temper-
LDC500 Series Laser Diode Controllers