4 – 40
Remote Operation
Front panel:
TE Cfg: Polarity
reversed: *N
.
TPOL?
Example:
NO
4.5.13
TEC sensor commands
Thermometer Type
TSNR(?)
{
z
}
Set (query) the temperature sensor type
{
to
z
=
(
NTC10UA 0
,
NTC100UA 1
,
NTC1MA 2
,
NTCAUTO 3
,
RTD 4
,
LM335 5
,
AD590 6
)
}
.
Four types of temperature sensors are supported by the LDC500:
thermistors (generally, NTC thermistors), RTDs (typically Pt-100 or
other PTC sensors), LM335 and compatible temperature-to-voltage
transducers, and AD590 and compatible temperature-to-current
transducers. RTDs and LM335s are biased with a 1 mA excitation
current, while the AD590 is biased with 5 V.
The user has several options in biasing the NTC thermistors. Typ-
ically, by selecting
TSNR
NTCAUTO
, the LDC500 will auto-range the
excitation current to the thermistor between 10
μ
A and 1 mA. Al-
ternately, the user can specify a fixed excitation current of 10
μ
A
(
NTC10UA
), 100
μ
A (
NTC100UA
), or 1 mA (
NTC1MA
). The sensor type
cannot be changed while the TEC is on and in CT control mode.
Front panel:
"#
468%
.
TSNR 3
Example:
Thermometer Excitation Current
TIEX(?)
{
z
}
Set (query) the thermometer excitation current
{
to
z
=
(
0
,
1
,
2
)
}
.
Typically, the temperature sensor excitation current is left at its de-
fault setting. In certain applications, however, a user may wish
to override the default, and force the excitation current to 10
μ
A
(
TIEX
0
), 100
μ
A (
TIEX
1
), or 1 mA (
TIEX
2
). Note that, if the sen-
sor is set to
TSNR
NTCAUTO
, the current autoranging will override
any manual setting provided by
TIEX
. Changing the
TIEX
setting for
AD590 or LM335 sensors will always result in a sensor fault.
The query form
TIEX?
can always be used to determine the sensor
excitation current in use.
There is no front panel equivalent to
TIEX
.
TIEX 1
Example:
LDC500 Series Laser Diode Controllers
