Sicon-8 Technical Manual
CircuitWerkes, Inc.
11
Metering & Status Connections
Eight metering channels are brought into the Sicon-8 on a depluggable euro-connector located at the center of the
back panel (see Figure 2 above). These analog inputs can handle either positive or negative voltages of up to 12 Volts,
however all inputs must be ground referenced by connecting your metering ground to the Sicon-8's ground. To make
setup and operation simpler, each input is auto-ranging. You do not have to adjust any potentiometers to set the proper
input range. Inputs are self-calibrating and are based on an internal, precision, low-drift, voltage reference, so the meters
will not drift over time or with temperature. Metering setup is as simple as connecting the sample voltage and then telling
the Sicon-8 what the input voltage represents. DO NOT CONNECT SAMPLE VOLTAGES IN EXCESS OF 12V OR
DAMAGE MAY OCCUR TO YOUR SICON-8.
Floating Grounds
Except for status input #8,
none
of the Sicon-8’s metering or status inputs will accept a floating ground.
Damage to the Sicon-8 or your equipment may result from connecting a floating ground output to the Sicon-8.
If you must use a metering or status inputs with equipment that has a floating ground, an isolation amplifier
must be used.
The Sicon-8's optically-isolated status inputs can be used to determine the status (on/off) of your
equipment. The status input connector is located immediately to the right of the metering connector and the
first seven status channels accept only contact closures as inputs. If the voltage at the input is at or very near
ground, then the status channel is considered active, and if it is ungrounded, the channel is considered
inactive. The logic can be reversed on each channel, in firmware, so that the status is considered active when
ungrounded. You can also choose to disconnect the Sicon-8's internal 5V supply and source your own
Voltage (up to 24V) to inputs 1-8. To Source Voltage, you must first move the “PWR SEL” jumper (JP517)
from “Int” to “Ext”. Be sure to never jumper both simultaneously. Then you connect your Voltage source to the
Ext input and ground of the “Stat Pwr” (JP-525) connector located just to the right of JP517. Internal 5V is also
brought out to the “Stat Pwr” connector should you want to use it for powering temperature probes, etc. Never
connect up an external Voltage source to the status inputs without moving Jumper JP517 to “Ext”.
Regardless of whether you use the internal Voltage source or your own, your equipment's ground must be tied
to the Sicon-8's ground.
In addition to the ability to source an external Voltage to the status inputs, the eighth status channel provides
some additional flexibility. Based on the “Ch8 SEL” (JP-517) jumper setting, you may configure channel 8 so
that your equipment sources current to or sinks current from the Sicon-8. In either case, if current is flowing,
then the input is considered active, but again, this may be inverted according to your preferences. If both
jumpers are removed from JP-517, you can supply your own, floating Voltage to channel 8’s + and – inputs. If
you don't want to source your own current to status channel 8, one line is provided with +5 V. This line is
diode-protected and current-limited. It is not required that a +5V line be used to source current to channel 8. It
will tolerate up to 24 VDC as input, but at least 3 VDC is needed to turn the optoisolator on. The status inputs
will not accept AC Voltages. If an AC input is required, a bridge rectifier with a small capacitor at its output
should be used to convert the sample to DC before connecting it to the Sicon-8's status input. As noted above
under metering, except for status input #8, connecting a floating ground to your unit may result in damage to
the Sicon-8 or the device that is connected to the Sicon-8. It will may also result in erroneous readings or
status indications.
Fig. 2 - Sicon-8 Back Panel
Diagram
Содержание Sicon-8
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