Emerson Fisher FLOBOSS 407, Instruction Manual

Page: 72 / 200

FloBoss 407 Instruction Manual
3-16 Rev 5/00
3.4.7 Discrete Output Source Module
A schematic representation of the field wiring connections to the output circuit of the Discrete Output
Source module is shown in Figure 3-13.
CAUTION
The Discrete Output Source module is designed to operate only with non-powered
discrete devices such as relay coils or solid-state switch inputs. Using the module
with powered devices may cause improper operation or damage to occur.
The Discrete Output Source module provides a switched voltage across terminals B and C that is
derived from internal voltage source V
s
. A field device, such as a relay coil, is energized when the
ROC/FloBoss electronics provides a voltage at terminals B and C. When V
s
is switched off by the
ROC/FloBoss electronics, the field device is no longer energized.
CAUTION
When using the Discrete Output Source module to drive an inductive load such as a
relay coil, a suppression diode should be placed across the input terminals to the
load. This protects the module from the reverse EMF spike generated when the
inductive load is switched off.
1 Amp
DOC0145A
+5V
DO SRC
V
S
CONTROL
I LIMIT
B
–
C
–
N/C
+
A
+
DISCRETE DEVICE
ROC-POWERED
Figure 3-13. Discrete Output Source Module Field Wiring