4 – 20
Remote Operation
See
PILM
, above, for a discussion of current and voltage limiting
when controlling a laser with a photodiode.
Front panel:
LD Settings:
Dlim:)-
.
PWLM500.0
Example:
4.5.5
Laser setting commands
Laser Diode Current On
/
O
ff
LDON(?)
{
z
}
Set (query) the laser diode excitation source
{
to
z
=
(
OFF 0
,
ON 1
)
}
.
The laser diode is turned on by issuing
LDON
ON
; following a 3-
second safety delay, the shunting relay is opened and the current
source is ramped up to the setpoint value. Turning the laser o
ff
, via
LDON
OFF
, is immediate.
Front-panel control is by the [LASER On
/
O
ff
] button.
LDON ON
Example:
Laser Diode Current Setpoint
SILD(?)
{
f
}
Set (query) the laser diode current setpoint
{
to
f
}
, in mA.
When the laser is operating in CC mode, the laser current setpoint is
controlled by
SILD
.
Front panel:
LD Settings:
D(:)*
.
SILD?
Example:
500.000
Photodiode Current Setpoint
SIPD(?)
{
f
}
Set (query) the monitor photodiode current setpoint
{
to
f
}
, in
μ
A.
When the laser is operating in CP mode, and
PDMW
NO
is set, the
laser current is controlled to maintain a constant photodiode current
at the level set by
SIPD
.
Front panel:
LD Settings:
D(:+,*
.
SIPD 123.4
Example:
LDC500 Series Laser Diode Controllers
