Lake Shore Model 218 Temperature Monitor User’s Manual
Operation
4-11
Filter (Continued)
Press
Enter
to continue. The eighth display of the Math setting sequence appears.
Use the Data Selection keys to select the number of filter points, from 2 to 64. Press
Enter
. The ninth
display of the Math setting sequence appears.
Use the Data Selection keys to select the filter window, from 1% to 10%, then press
Enter
to return to
the normal display.
Press
Escape
at any time to return to the normal display. The instrument retains values changed
prior to pressing
Escape
.
4.8 ANALOG OUTPUTS (MODEL 218S ONLY)
The Model 218S has two analog voltage outputs numbered 1 and 2. They are commonly configured to
send a voltage proportional to temperature to a strip chart recorder or data acquisition system. The
outputs can also be manually controlled as a voltage source for any other application.
The analog outputs are variable DC voltage sources that can vary from +10V to –10V. The voltage is
generated by a 14-bit D/A converter with resolution of 1.25 mV or 0.0125% of full scale. The output is
short protected but should never be used to drive a resistance lower than 1 k
Ω
. Analog output terminals
are in the detachable terminal block on the Model 218S rear panel.
The analog outputs each have three modes of operation: off, input, and manual. Once a mode is
selected, the parameters associated with that mode follow on setting screens. The two outputs are
configured independently and can have different modes.
To set the operating mode of an analog output, press
Analog Outputs
. The first display appears. Use
the Data Selection keys to choose which output to configure (
1
-
2
), the press
Enter
.
The second display in the setting sequence appears. Use the Data Selection keys to cycle through
different modes for the selected analog output (
Off
,
Manual
,
Input
). When the desired mode appears,
press
Enter
to assign that mode to the selected output.
Analog Output OFF
Select Off to set the selected analog output to zero volts and return to the normal display.
Analog Output Manual Mode
Select Manual to control output voltage from the front panel. After selecting manual mode, select
unipolar or bipolar operation, then press Enter. Set the output value in percent with a range of –
100.00% to +100.00% corresponding to –10 V to +10 V. The setting resolution is 0.01%, but actual
output voltage resolution is 0.0125%. Press Enter again to return to the Normal display.