Teledyne API T703/T703U Calibrator Operation Manual Getting Started
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CONNECTING THE STATUS OUTPUTS 3.2.3.
The status outputs report calibrator conditions via optically isolated NPN
transistors, which sink up to 50 mA of DC current. These outputs can be used
interface with devices that accept logic-level digital inputs, such as programmable
logic controllers (PLCs). Each Status bit is an open collector output that can
withstand up to 40 VDC. All of the emitters of these transistors are tied together
and available at D.
NOTE
Most PLCs have internal provisions for limiting the current that the input will draw from an
external device. When connecting to a unit that does not have this feature, an external dropping
resistor must be used to limit the current through the transistor output to less than 50 mA. At 50
mA, the transistor will drop approximately 1.2V from its collector to emitter.
The status outputs are accessed via a 12-pin connector on the calibrator‟s rear
panel labeled STATUS. The function of each pin is defined in Table 3-3.
CALIBRATOR
INRTERNAL GROUND
Figure 3-10: Status Output Connector
The pin assignments for the Status Outputs are:
Table 3-3: Status Output Pin Assignments
On, if no faults are present.
On if the calibrator is in GENERATE mode
On if the calibrator is in DIAGNOSTIC mode
On whenever a temperature alarm is active.
On whenever gas pressure alarm is active
The emitters of the transistors on pins 1 to 8 are bussed together.
The ground level from the calibrator‟s internal DC power supplies.
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