Teledyne 3000PAEU - General purpose percent oxygen analyzer User Manual

Page 32

3 Installation

Model 3000PA

3-10

Teledyne Analytical Instruments

In addition, each individual line has a series FET with a nominal ON

resistance of 5 ohms (9 ohms worst case). This can limit the obtainable
voltage, depending on the load impedance applied. See Figure 3-6.

Figure 3-6: FET Series Resistance

3.3.2.3

RS-232 Port: The digital signal output is a standard RS-232

serial communications port used to connect the analyzer to a computer,
terminal, or other digital device. It requires a standard 9-pin D connector.

The data is status information, in digital form, updated every two

seconds. Status is reported in the following order:

•

The concentration in percent

•

The range in use (HI, MED, LO)

•

The span of the range (0-10 %, etc)

•

Which alarms—if any—are disabled (AL–x DISABLED)

•

Which alarms—if any—are tripped (AL–x ON).

Each status output is followed by a carriage return and line feed.

Four input functions using RS-232 have been implemented to date.

They are described in Table 3-1.

Table 3-1: Commands via RS-232 Input

Command

Description

Immediately starts an autospan.

Immediately starts an autozero.

Reports "Raw Cell Output" (current output of the sensor
itself) in

A. For example—

Raw Cell Output: 99 µA.