Fisher DPR900 User Manual page 27

2.5
Route a 14 AWG (1.5 mm*) conductor from terminal 36 to the
instrumentation system dc ground point. Then run a 10 AWG (5.26
mm*) multistrand conductor from the instrumentation system dc
ground point to the existing plant ground grid. This point on the plant
ground grid must be dedicated exclusively to the instrumentation
system dc ground and must not be used for other equipment
grounding. Use crimped or thermal-welded connections at all ground
points.
Jumper Module
@
Caution
Ensure that power to the controller is OFF,
prior to cutting jumpers. Leave sufficient
metal to solder jumper back together if
required.
The jumpers on the back of the mounting cassette determine the
electrical termination characteristics of the four analog inputs and the
RS-485 communications wiring. All of the analog inputs, All thru Al4,
have 250 ohm input resistors. There is also a 100 ohm termination
resistor on the RS-485 connection. The figure shows the jumper
module and the table describes the connection each jumper makes.
input resistor Al2
Input resistor
A14
Floating ground All
Floating ground Al2
Floating ground Al3
Floating ground Al4
Current In
Current In
current In
Current In
Fixed GND
Fixed GND
Fixed GND
Fixed GND
YES
Voltage In
Voltage In
Voltage In
Voltage In
Floating GND
Floaring GND
Floating GND
Floating GND
NO
Jumpers 1 thru 4 connect the 250 ohm input resistors in series so
that the 4-20 mA input signal can be converted to a I -5V signal inter-
nally. Cut the appropriate jumper to accept a direct l-5V signal on
1...5...!3
the input terminals. Jumpers 5 thru 8 connect inputs All thru Al4 to
DPR90c-5% the controller
supply ground. Cut the appropriate jumper to allow the
negative input terminal to float between -5 V and 17 V, with respect
to supply ground.
May 1991 UM61:DPR900:9102