Teledyne T101, Руководство по эксплуатации, Страница: 147 / 375

Teledyne ML – T101 Operation Manual Remote Operation
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5. REMOTE OPERATION
5.1.1. REMOTE OPERATION USING THE EXTERNAL DIGITAL I/O
5.1.1.1. Status Outputs
The status outputs report analyzer 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 (PLC’s). 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 PLC’s 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 through a 12 pin connector on the analyzer’s rear panel
labeled STATUS (see Figure 5-1). The function of each pin is defined in Table 5–1.