Lake Shore Model 331 Temperature Controller User’s Manual
4.16 ANALOG OUTPUT (Model 331S Only)
The Model 331S has a single analog output on Pins 7 and 8 of the terminal block at the rear of the
instrument. It is normally configured to send a voltage proportional to temperature to a strip chart
recorder or separate data acquisition system. The output can also be manually controlled as a voltage
source for any other application or used as the control output for Loop 2.
The analog output is a variable DC voltage source that can vary from +10V to –10V. The voltage is
generated by a 16-bit D/A converter with resolution of 0.3 mV or 0.003% of full scale. The output is
short-circuit protected but should never be used to drive a resistance lower than 100
Ω
. When acting as
the Loop 2 heater, the output can provide up to 1 W of power (0.1 A into a 100
Ω
minimum heater load).
For further specifications, refer to the Loop 1 and 2 comparison table in Paragraph 1.X.
The analog output has four modes of operation: Off, Input, Manual, and Loop 2. If you select Off, the
analog output is set to 0 volts and you are returned to the normal display. Once a mode is selected, the
parameters associated with that mode follow on setting screens.
4.16.1 Analog Output In Input Mode
In Input mode, the analog output will track the input according to scaling parameters entered by the
user. Press the
Analog Output
key.
Select with °®
Analog Out Input A
Press the
s
or
t
key until Input A is showing. Press the
Enter
key.
Select for AnOut °®
Source Temp K
Press the
s
or
t
key to cycle through the data source units: Temp K, Temp C, Sensor, or Linear,
where K = kelvin, C = Celsius, Sensor = volts (V) or ohms (
Ω
), and Linear = MX+B or M(X+B) (refer
to Paragraph 4.14.2). For this example, choose Temp K. Press the
Enter
key.
Select for AnOut °®
Bipolar Mode On
Press the
s
or
t
key to toggle between Bipolar Mode On or Off.
4-32
Operation
