DYNISCO SC170 Manual
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3.1.1 Factory Configuration
Milliampere mode, Analog Output
4.00mA Input
= 4.00mA Output
20.00mA Input
= 20.00mA Output
Sensor Fail-safe
= 21.00mA
On special request the factory will set the signal conditioner to any
desired configuration. Special configurations are identified on a tag
attached to the unit.
3.1.2 Analog Operating Mode
If the unit was ordered with the standard factory configuration, the
input required is a 4 to 20mA current loop. The packing slip should
indicate if the unit was set up to any other customer requested special
configuration. If there is a need to change the configuration of the
signal conditioner, or to re-range it, refer to the procedures described
in SECTION 4.
NOTE
: Even when “In a Hurry”, the use of an appropriate power
supply is important. A 24V DC supply having a current handling
capacity of at least 0.1A is commonly used. Do not use a power
supply whose output voltage drops to 20 volts or below when a
0.1 ampere load is connected to it. Always use a DC (direct
current) supply, or suitable size battery. Never connect the signal
conditioner directly to 115VAC.
With the power supply off, connect the + side of the power supply to
the +OUT terminal of the signal conditioner. Connect the - side of the
power supply through an optional 250 ohm resistor to the -OUT (9)
terminal of the signal conditioner. Connect the input terminals 6 and
7 in series with the current loop to be measured. Terminal 6 should
be more positive than 7.
Current Input High (+MA) (6)
Current Input Low (-COM) (7)
To connect other sensors to the input refer to Section 2.3.32 for the
proper sensor connections.
The output can be monitored by connecting a milliammeter in series
with either of the two output terminals, or by connecting a high
impedance voltmeter across the optional 250 ohm resistor. Now
turn on the power supply. In about 5 seconds the SC170 loop current
will settle to its normal value in the range of 4 to 20mA. In this
configuration the SC170 is a loop-powered isolator. The output
current will duplicate the current applied to the input terminals.
