52 Chapter 4 Temperature Controller Module Operation
or Const R mode when the temperature limit is exceeded (if the output off bits are
enabled for this condition).
Caution: these limits do not apply if the sensor type is set to “None.”
4.4.3.5.3 Resistance/Reference Limits (Limit R
HI
/v
HI
/i
HI
and Limit R
LO
/v
LO
/i
LO
)
Like the temperature limits, the 8300/8600 also supports both a low and high
resistance/reference limit, and can be programmed to turn the TEC output off in the
event those limits are exceeded, although by default this is disabled. These limits are
monitored only while in Const R/v/i mode.
4.4.3.6 Tolerances (Tol Time and Tol Temp)
The
Tol Time
and
Tol Temp
elements are used for determining when the 8300 is “in
tolerance,” where the actual temperature has stayed within
Tol Temp
of the set point
for at least
Tol Time
seconds. The
Tol Time
value is expressed in seconds, and can
range from 0.001 seconds to 50 seconds. The
Tol Temp
value is displayed in ºC (the
most common usage), and can range from 0.01 to 10.00. If at any time it goes outside
the tolerance range, the time restarts at zero.
As an example, if the
Tol Time
is set to 5 seconds, the
Tol Temp
is set to 0.2ºC, and
the temperature set point was 25.0ºC, the TEC module would have to stay within
24.8ºC and 25.2ºC to be within tolerance. Out of tolerance is indicated by a
Out Of
Tol
status field on the bottom of the TEC Main Screen.
The out of tolerance condition is most often used to shutdown laser outputs when a
TEC is not operating within tolerance. This can be done in one of two ways. The
first, and simplest, would be to define a link condition with the TEC module as the
source,
Out of Tol
as the condition,
Turn Off
as the action, and the laser module as
the target.
Alternately, if the system was being operated over IEEE-488 or RS-232, once the
TEC was within tolerance, its OUTOFF register could be set to turn the TEC off
when out of tolerance. Then enable the TEC OFF bit in the laser’s OUTOFF register.
This will cause the TEC to shutdown when it goes out of tolerance, and the laser to
shutdown because the TEC is OFF. The disadvantage of this second method would
be that the laser would shutdown if
any
TEC were off, which might not be the desired
operation. Also, you would have to disable the Out of Tolerance bit in the TEC’s
OUTOFF register before you could turn the TEC back on.
4.4.3.7 Prev soft key
Pushing the
Prev
soft key returns to the previous screen.
4.4.4 Link Conditions
The Laser module supports the following link conditions:
Artisan Technology Group - Quality Instrumentation ... Guaranteed | (888) 88-SOURCE | www.artisantg.com
To Next Page
Loading...
