1 – 4
Getting Started
The right-most digit (after
) is the power of ten exponent.
For example, the display
=
1200.
•
The
P
parameter has a selectable “
±
” indicator before the
mantissa.This allows the polarity of the controller to be tog-
Polarity
=
⇒
gled by the user. All other exponentially displayed parameters
are unipolar, so no sign is displayed for these parameters.
•
In fixed decimal format a value between
−
10 and
+
10 may be
selected using [ ] (and [Shift]).
•
The two outputs,
P
×
ε
, and
Output
, are accompanied by bar
displays on the right side of the front panel.
P
×
ε
simply
ranges from
−
10 V to
+
10 V. However, since the controller out-
put ranges between the user-programmed upper and lower
limits, the output bar display is normalized to that range. For
example, if the limits were set to
+
5 V and
−
1 V, the full range
of the bar display would be 6 V, and 0 V would no longer cor-
respond to the center of the bar display, but would be
1
/
6
th
of
the way up from the bottom. The default limits are
±
10 V.
•
Use [Setpoint] in the INPUTS section of the front panel to
choose between an external setpoint input, and the internally
generated setpoint. An external setpoint can be supplied at the
Setpoint BNC input. When the internal setpoint is selected the
BNC connector is disconnected from the SIM960 circuitry.
•
The Output BNC connector can be toggled between PID Con-
trol mode and Manual mode using [Output] (in the OUTPUT
section of the front panel). In manual mode, the SIM960 output
is set to the value indicated by the manual parameter.
1.2.1
Inputs
The common mode range of the “Measure” and “Setpoint” inputs
extends from
−
10 V to
+
10 V. If either input is outside this range, the
overload LED indicator lights.
The di
ff
erential input range is
±
1 V. Whenever the di
ff
erence between
Setpoint and Measure exceeds this range, the overload LED indica-
tor turns on. When connected with overall negative feedback and
reasonably well tuned, the SIM960 keeps the di
ff
erence between the
setpoint and measure inputs as small as possible, so the di
ff
erential
input range is unlikely to be exceeded. Before the SIM960 has been
tuned for a given system, however, this may not be true. It is helpful
to keep in mind that exceeding the
±
1 V di
ff
erential input range will
saturate the error amplifier, even if the output signal would otherwise
be within the upper and lower
Limits
setting. In such situations, the
controller will be e
ff
ectively limited at some intermediate value.
SIM960 Analog PID Controller
