5
6) Using the knob, set the desired time (off to 30 minutes).
7) Press
again to store the value and return the unit to normal
mode. The stored value will remain in memory until changed by the
operator.
B. HART Resistor Setup
The PCL120 incorporates an internal 250 ohm resistor to facilitate using a
Rosemount 275 Communicator during calibration or installation of HART
transmitters. The internal resistor takes the place of the 250 ohm resistor
normally installed during the use of the model 275 Communicator. An
internal jumper can be removed to enable this feature if desired. The unit
is shipped with the jumper in place. To remove the jumper open the case
and refer to
Figure 2
to locate the jumper, then pull off the jumper to
enable the resistor. The jumper can be stored outside of the unit or re-
installed only on one pin so that the circuit remains open.
Figure 2
Note : When the 250 ohm resistor is enabled the load driving capability is
reduced from 1200 ohms to 950 ohms. In most cases this should not be a
problem when calibrating Non-HART compatible products.
4. Basic Operating Modes
The PCL120 offers 4 modes of milliamp operation and one voltage
measure mode. The following text and figures explain the various
operating modes:
A. Milliamp Source
Figure 3
shows a typical application where the PCL120 is sourcing 4 to 20
mA into a device under test.
AUTO
®
®
®