Teledyne 460H Digital Status Outputs, 1 Digital Status Output Pins, Label, Name, Operation

2.4.2 Digital Status Outputs

The M460H has four digital status outputs for indicating error and operational status conditions. These outputs are in the form of opto-isolated open-collector transistors. They can be used to drive status LED’s on a display panel or interface to a digital device such as a Programmable Logic Controller (PLC).

Figure 2-4 shows the most common way of connecting the digital outputs to an external device such as PLC. Note: Most devices, such as PLC’s, have internal provision for limiting the current that the input will draw from an external device. When connecting to a unit that does not have this feature, external dropping resistors must be used to limit the current through the transistor output to 50mA or less.

See Chapter 7 for details on using the Status Outputs for diagnosing sensor and system- level malfunctions.

Table 2-1 below describes the function of the status outputs.

Table 2-1 Digital Status Output Pins

Label	Name	Operation
STATUS OUT 1	Sensor O.K.	Normally On
STATUS OUT 2	Invalid Reading	Normally Off
STATUS OUT 3	Lamp Low	Normally Off
STATUS OUT 4	Cell Dirty	Normally Off
STATUS OUT 5	Auto-Zero Error	Normally Off
STATUS OUT 6	Spare	Undefined
STATUS COM	Common Pin for	N/A
	all Status Outputs

M454		Programmable Logic
		Controller or other device
		+5V
Digital	Output #1-4 (Collector)	Digital
		Input
Digital Output Common (Emmiter)
Opto-Isolator		Ground Provided
		by PLC

Figure 2-4 Digital Output Connections

P/N 03662D Teledyne API Model 460H O3 Monitor Operator Manual - Page 15